CVE-2026-23490
published 2026-01-16CVE-2026-23490: pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed…
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.68%
48.8th percentile
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
Affected
126 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform-24 | ee-minimal-rhel8 | — | — |
| ansible-automation-platform-24 | ee-minimal-rhel9 | — | — |
| ansible-automation-platform-24 | ee-supported-rhel8 | — | — |
| ansible-automation-platform-24 | ee-supported-rhel9 | — | — |
| ansible-automation-platform-24 | lightspeed-rhel8 | — | — |
| ansible-automation-platform-24 | platform-resource-runner-rhel8 | — | — |
| ansible-automation-platform-25 | ee-supported-rhel8 | — | — |
| ansible-automation-platform-25 | lightspeed-chatbot-rhel8 | — | — |
| ansible-automation-platform-25 | lightspeed-rhel8 | — | — |
| ansible-automation-platform-26 | controller-rhel9 | — | — |
| ansible-automation-platform-26 | controller-rhel9-operator | — | — |
| ansible-automation-platform-26 | eda-controller-rhel9 | — | — |
| ansible-automation-platform-26 | eda-controller-rhel9-operator | — | — |
| ansible-automation-platform-26 | ee-supported-rhel9 | — | — |
| ansible-automation-platform-26 | gateway-rhel9 | — | — |
| ansible-automation-platform-26 | gateway-rhel9-operator | — | — |
| ansible-automation-platform-26 | hub-rhel9 | — | — |
| ansible-automation-platform-26 | hub-rhel9-operator | — | — |
| ansible-automation-platform-26 | lightspeed-chatbot-rhel9 | — | — |
| ansible-automation-platform-26 | lightspeed-rhel9 | — | — |
| ansible-automation-platform-26 | lightspeed-rhel9-operator | — | — |
| ansible-automation-platform-26 | platform-resource-rhel9-operator | — | — |
| ansible-automation-platform-27 | aap-cloud-billing-operator-rhel9 | — | — |
| ansible-automation-platform-27 | controller-rhel9 | — | — |
| ansible-automation-platform-27 | controller-rhel9-operator | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
ghsa7.5HIGH
osv7.5HIGH
vendor_debian7.5HIGH
vendor_redhat7.5HIGH
vendor_ubuntu7.5HIGH
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GHSA
pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service
ghsa·2026-07-21·CVSS 7.5
CVE-2026-59885 [HIGH] CWE-400 pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service
pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service
### Impact
The BER/CER/DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs. A small crafted payload (tens of kilobytes) containing an OID with many arcs consumes seconds of CPU per decode() call, allowing denial of service in any application that decodes untrusted ASN.1 data (certificates, LDAP, SNMP, Kerberos, etc.). The corresponding encoders have the same quadratic behavior, reachable when an application re-encodes previously decoded attacker-supplied values.
The arc-size limit introduced for CVE-2026-23490 bounds the byte length of an individual arc but not the number of arcs, so it does not mitigate this issue.
### Affect
OSV
pyasn1 vulnerabilities
osv·2026-03-30·CVSS 7.5
CVE-2026-23490 [HIGH] pyasn1 vulnerabilities
pyasn1 vulnerabilities
It was discovered that pyasn1 could exhaust system resources when
attempting to decode a malformed certificate. An attacker could
possibly use this to cause a denial of service. (CVE-2026-23490)
Kevin Tu discovered that pyasn1 could exhaust system resources via
uncontrolled recursion when attempting to decode malicously-crafted
certificates. An attacker could possibly use this to cause a denial of
service. (CVE-2026-30922)
OSV
CVE-2026-30922: pyasn1 is a generic ASN
osv·2026-03-18·CVSS 7.5
CVE-2026-30922 [HIGH] CVE-2026-30922: pyasn1 is a generic ASN
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this spe
GHSA
pyasn1 has a DoS vulnerability in decoder
ghsa·2026-01-16
CVE-2026-23490 [HIGH] CWE-400 pyasn1 has a DoS vulnerability in decoder
pyasn1 has a DoS vulnerability in decoder
### Summary
After reviewing pyasn1 v0.6.1 a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets.
### Details
The integer issue can be found in the decoder as `reloid += ((subId 10000:
print(f'[!] MEMORY EXPLOSION: {len(str_result)} character string!')
except MemoryError:
print(f'[-] MemoryError during string conversion!')
except Exception as e:
print(f'[-] {type(e).__name__} during string conversion')
except MemoryError:
print('[-] MemoryError: Out of memory!')
except Exception as e:
print(f'[-] Error: {type(e).__name__}: {e}')
print("\n[*] Test completed")
```
Screenshots with the results:
#### DoS
#### Leak analysis
A potential heap leak was investigate
OSV
CVE-2026-23490: pyasn1 is a generic ASN
osv·2026-01-16·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490: pyasn1 is a generic ASN
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
OSV
pyasn1 has a DoS vulnerability in decoder
osv·2026-01-16
CVE-2026-23490 [HIGH] pyasn1 has a DoS vulnerability in decoder
pyasn1 has a DoS vulnerability in decoder
### Summary
After reviewing pyasn1 v0.6.1 a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets.
### Details
The integer issue can be found in the decoder as `reloid += ((subId 10000:
print(f'[!] MEMORY EXPLOSION: {len(str_result)} character string!')
except MemoryError:
print(f'[-] MemoryError during string conversion!')
except Exception as e:
print(f'[-] {type(e).__name__} during string conversion')
except MemoryError:
print('[-] MemoryError: Out of memory!')
except Exception as e:
print(f'[-] Error: {type(e).__name__}: {e}')
print("\n[*] Test completed")
```
Screenshots with the results:
#### DoS
#### Leak analysis
A potential heap leak was investigate
Red Hat
pyasn1: python-pyasn1: pyasn1: Denial of Service via crafted ASN.1 OBJECT IDENTIFIER
vendor_redhat·2026-07-14·CVSS 7.5
CVE-2026-59885 [HIGH] CWE-1050 pyasn1: python-pyasn1: pyasn1: Denial of Service via crafted ASN.1 OBJECT IDENTIFIER
pyasn1: python-pyasn1: pyasn1: Denial of Service via crafted ASN.1 OBJECT IDENTIFIER
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a small crafted payload containing an OID with many arcs consumes excessive CPU per decode() call and can deny service to applications that decode untrusted ASN.1 data. The corresponding encoders have the same quadratic behavior when an application re-encodes previously decoded attacker-supplied values. This issue is fixed in version 0.6.4.
A flaw was found in pyasn1, a Python library for Abstract Syntax Notation One (ASN.1). The BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in qua
Ubuntu
pyasn1 vulnerabilities
vendor_ubuntu·2026-03-30·CVSS 7.5
CVE-2026-23490 [HIGH] pyasn1 vulnerabilities
Title: pyasn1 vulnerabilities
Summary: Several security issues were fixed in pyasn1.
It was discovered that pyasn1 could exhaust system resources when
attempting to decode a malformed certificate. An attacker could
possibly use this to cause a denial of service. (CVE-2026-23490)
Kevin Tu discovered that pyasn1 could exhaust system resources via
uncontrolled recursion when attempting to decode malicously-crafted
certificates. An attacker could possibly use this to cause a denial of
service. (CVE-2026-30922)
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
vendor_redhat·2026-03-18·CVSS 7.5
CVE-2026-30922 [HIGH] CWE-835 pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTET
Ubuntu
pyasn1 vulnerability
vendor_ubuntu·2026-01-22
CVE-2026-23490 pyasn1 vulnerability
Title: pyasn1 vulnerability
Summary: pyasn1 could be made to crash if it received specially crafted input.
It was discovered that pyasn1 incorrectly handled malformed RELATIVE-OIDs
with excessive continuation octets. An attacker could possibly use this
issue to cause pyasn1 to consume memory, leading to a denial of service.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
vendor_redhat·2026-01-16·CVSS 7.5
CVE-2026-23490 [HIGH] CWE-770 pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
A flaw was found in pyasn1, a generic ASN.1 library for Python. A remote attacker could exploit this vulnerability by sending a specially crafted RELATIVE-OID with excessive continuation octets. This input validation vulnerability leads to memory exhaustion, resulting in a Denial of Service (DoS) for the affected system.
Package: workload-availability/fence-agents-remediation-rhel9-operator (Fence Agents Remediation Operator) - Affected
Package: rhmtc/openshift-migrat
Debian
CVE-2026-23490: pyasn1 - pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Servic...
vendor_debian·2026·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490: pyasn1 - pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Servic...
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
Scope: local
bookworm: resolved (fixed in 0.4.8-3+deb12u1)
bullseye: resolved (fixed in 0.4.8-1+deb11u1)
forky: resolved (fixed in 0.6.2-1)
sid: resolved (fixed in 0.6.2-1)
trixie: resolved (fixed in 0.6.1-1+deb13u1)
Debian
CVE-2026-30922: pyasn1 - pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` libra...
vendor_debian·2026·CVSS 7.5
CVE-2026-30922 [HIGH] CVE-2026-30922: pyasn1 - pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` libra...
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this spe
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-23490 python38-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
bugzilla·2026-04-22·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490 python38-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
CVE-2026-23490 python38-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-23490 python39-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
bugzilla·2026-04-22·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490 python39-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
CVE-2026-23490 python39-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-23490 python3.11-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
bugzilla·2026-04-22·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490 python3.11-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
CVE-2026-23490 python3.11-pyasn1-epel: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-30922 pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
bugzilla·2026-03-18·CVSS 7.5
CVE-2026-30922 [HIGH] CVE-2026-30922 pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
CVE-2026-30922 pyasn1: pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CON
Bugzilla
CVE-2026-23490 pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
bugzilla·2026-01-16·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490 pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
CVE-2026-23490 pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:1904 https://access.redhat.com/errata/RHSA-2026:1904
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2026:1905 https://access.redhat.com/errata/RHSA-2026:1905
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:1906 https://access.redhat.
Wiz
CVE-2026-23490 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2026-23490 [HIGH] CVE-2026-23490 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-23490 :
Python vulnerability analysis and mitigation
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.
Source : NVD
## 7.5
Score
Published January 16, 2026
Severity HIGH
CNA Score 7.5
Affected Technologies
Python
Rocky Linux
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 5.7
Exploitation Probability (EPSS) N/A
Affected packages and libraries
open-webui
fence-agents-bladecenter
Sources
NVD
AlmaLinux 8 Severity HIGH Has Fix Added at: Feb 11, 2026
AlmaLinux 9 Severity HIGH Has Fix Ad
https://github.com/pyasn1/pyasn1/commit/3908f144229eed4df24bd569d16e5991ace44970https://github.com/pyasn1/pyasn1/releases/tag/v0.6.2https://github.com/pyasn1/pyasn1/security/advisories/GHSA-63vm-454h-vhhqhttps://lists.debian.org/debian-lts-announce/2026/02/msg00002.htmlhttps://access.redhat.com/errata/RHSA-2026:13508https://access.redhat.com/errata/RHSA-2026:13512https://access.redhat.com/errata/RHSA-2026:13545https://access.redhat.com/errata/RHSA-2026:13553https://access.redhat.com/errata/RHSA-2026:14020https://access.redhat.com/errata/RHSA-2026:17446https://access.redhat.com/errata/RHSA-2026:17595https://access.redhat.com/errata/RHSA-2026:17611https://access.redhat.com/errata/RHSA-2026:1903https://access.redhat.com/errata/RHSA-2026:1904https://access.redhat.com/errata/RHSA-2026:1905https://access.redhat.com/errata/RHSA-2026:1906https://access.redhat.com/errata/RHSA-2026:19712https://access.redhat.com/errata/RHSA-2026:2221https://access.redhat.com/errata/RHSA-2026:2299https://access.redhat.com/errata/RHSA-2026:2300https://access.redhat.com/errata/RHSA-2026:2302https://access.redhat.com/errata/RHSA-2026:2303https://access.redhat.com/errata/RHSA-2026:2309https://access.redhat.com/errata/RHSA-2026:24476https://access.redhat.com/errata/RHSA-2026:24483https://access.redhat.com/errata/RHSA-2026:2453https://access.redhat.com/errata/RHSA-2026:2460https://access.redhat.com/errata/RHSA-2026:2483https://access.redhat.com/errata/RHSA-2026:2486https://access.redhat.com/errata/RHSA-2026:24866https://access.redhat.com/errata/RHSA-2026:24977https://access.redhat.com/errata/RHSA-2026:2712https://access.redhat.com/errata/RHSA-2026:2758https://access.redhat.com/errata/RHSA-2026:28042https://access.redhat.com/errata/RHSA-2026:30088https://access.redhat.com/errata/RHSA-2026:3354https://access.redhat.com/errata/RHSA-2026:3359https://access.redhat.com/errata/RHSA-2026:37275https://access.redhat.com/errata/RHSA-2026:3958https://access.redhat.com/errata/RHSA-2026:3959https://access.redhat.com/errata/RHSA-2026:39894https://access.redhat.com/errata/RHSA-2026:4138https://access.redhat.com/errata/RHSA-2026:4139https://access.redhat.com/errata/RHSA-2026:4140https://access.redhat.com/errata/RHSA-2026:4141https://access.redhat.com/errata/RHSA-2026:4142https://access.redhat.com/errata/RHSA-2026:4143https://access.redhat.com/errata/RHSA-2026:4144https://access.redhat.com/errata/RHSA-2026:4145https://access.redhat.com/errata/RHSA-2026:4146https://access.redhat.com/errata/RHSA-2026:4147https://access.redhat.com/errata/RHSA-2026:4148https://access.redhat.com/errata/RHSA-2026:41928https://access.redhat.com/errata/RHSA-2026:42644https://access.redhat.com/errata/RHSA-2026:4943https://access.redhat.com/errata/RHSA-2026:5606https://access.redhat.com/security/cve/CVE-2026-23490https://bugzilla.redhat.com/show_bug.cgi?id=2430472https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23490.json
2026-01-16
Published