CVE-2026-34874
published 2026-04-01CVE-2026-34874: An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an…
PriorityP338high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.28%
20.1th percentile
An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | mbedtls | — | — |
| trustedfirmware | mbed_tls | — | — |
| trustedfirmware | mbed_tls | >= 3.5.0 < 3.6.6 | 3.6.6 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
osv7.5HIGH
vendor_debian7.5HIGH
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OSV
CVE-2026-34874: (An issue was discovered in Mbed TLS through 3
osv·2026-04-02·CVSS 7.5
CVE-2026-34874 [HIGH] CVE-2026-34874: (An issue was discovered in Mbed TLS through 3
(An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0. ...)
GHSA
GHSA-5jpv-5p2x-4fwv: An issue was discovered in Mbed TLS through 3
ghsa_unreviewed·2026-04-01
CVE-2026-34874 [HIGH] CWE-476 GHSA-5jpv-5p2x-4fwv: An issue was discovered in Mbed TLS through 3
An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
OSV
CVE-2026-34874: An issue was discovered in Mbed TLS through 3
osv·2026-04-01·CVSS 7.5
CVE-2026-34874 [HIGH] CVE-2026-34874: An issue was discovered in Mbed TLS through 3
An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
Debian
CVE-2026-34874: mbedtls - An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There i...
vendor_debian·2026·CVSS 7.5
CVE-2026-34874 [HIGH] CVE-2026-34874: mbedtls - An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There i...
An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
Scope: local
bookworm: open
bullseye: open
forky: open
sid: open
trixie: open
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-34874 micropython: NULL pointer dereference when setting a distinguished name [fedora-all]
bugzilla·2026-04-01·CVSS 7.5
CVE-2026-34874 [HIGH] CVE-2026-34874 micropython: NULL pointer dereference when setting a distinguished name [fedora-all]
CVE-2026-34874 micropython: NULL pointer dereference when setting a distinguished name [fedora-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.
Discussion:
This is an mbedtls CVE, micropython is not affected as it doesn't call mbedtls_x509_string_to_names().
Bugzilla
CVE-2026-34874 mbedtls: NULL pointer dereference when setting a distinguished name [fedora-all]
bugzilla·2026-04-01·CVSS 7.5
CVE-2026-34874 [HIGH] CVE-2026-34874 mbedtls: NULL pointer dereference when setting a distinguished name [fedora-all]
CVE-2026-34874 mbedtls: NULL pointer dereference when setting a distinguished name [fedora-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.
Discussion:
FEDORA-2026-10443c65e3 (mbedtls-3.6.6-1.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-10443c65e3
---
FEDORA-2026-3a9536df40 (mbedtls-3.6.6-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3a9536df40
---
FEDORA-2026-8c332fbf00 (mbedtls-3.6.6-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026
Wiz
CVE-2026-34874 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 5.1
CVE-2026-34874 [MEDIUM] CVE-2026-34874 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-34874 :
Mbed TLS vulnerability analysis and mitigation
An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
Source : NVD
## 7.5
Score
Published April 1, 2026
Severity HIGH
CNA Score 7.5
Affected Technologies
Mbed TLS
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) 22
Exploitation Probability (EPSS) 0.1
Affected packages and libraries
mbedtls
cpe:2.3:a:arm:mbed_tls
Sources
Debian 11, 12, 13, 14 Severity HIGH No Fix Added at: Apr 02, 2026
Echo Severity HIGH No Fix Added at: Apr 02, 2026
Linux Severity HIGH Has Fix Added at: Apr 05, 2026
2026-04-01
Published