CVE-2026-81642
published 2026-09-16CVE-2026-81642: In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code…
PriorityP265critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.96%
60.3th percentile
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| nlnet_labs | unbound | < 1.26.1 | 1.26.1 |
| nlnetlabs | unbound | < 1.26.1 | 1.26.1 |
| nlnetlabs | unbound | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv4.09.1CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Red
vendor_redhat9.1CRITICAL
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Red Hat
unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
vendor_redhat·2026-09-16·CVSS 9.1
CVE-2026-81642 [CRITICAL] CWE-122 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.
A flaw was found in Unbound's DNSSEC validator. A remote attacker can exploit this vulnerability by controlling a malicious zone and sending a specially crafted DNSKEY record. This can lead to a heap buffer overflow, potentially res
GHSA
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs.
ghsa_unreviewed·2026-09-16
CVE-2026-81642 [CRITICAL] CWE-122 In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs.
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.
No detection rules found.
No public exploits indexed.
Bugzilla
[Minor Incident] CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY [fedora-all]
bugzilla·2026-09-17·CVSS 9.1
CVE-2026-81642 [CRITICAL] [Minor Incident] CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY [fedora-all]
[Minor Incident] CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY [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.
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zon
Bugzilla
CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
bugzilla·2026-09-16·CVSS 9.1
CVE-2026-81642 [CRITICAL] CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
CVE-2026-81642 unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.
Hackernews
⚡ Weekly Recap: Cisco 0-Day, AI Agent RCE, ClickFix Attacks, ClickFix Surge, and Browser Hijacks
blogs_hackernews·2026-09-21·CVSS 10.0
CVE-2026-76460 [CRITICAL] ⚡ Weekly Recap: Cisco 0-Day, AI Agent RCE, ClickFix Attacks, ClickFix Surge, and Browser Hijacks
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## ⚡ Weekly Recap: Cisco 0-Day, AI Agent RCE, ClickFix Attacks, ClickFix Surge, and Browser Hijacks
A browser. A plugin. A package. A login screen. Normal stuff. That is basically the problem this week.
The trouble keeps showing up inside things people already trust: code that takes a bad turn, old payloads coming back, exposed systems, weak checks, fake fixes, and attack paths that look almost too easy. Even the research side is getting messy, with more findings, more automation, and not always more clarity.
Nothing here needs much drama. Just a lot of small doors left open. Here’s what happened.
## ⚡ Threat of the Week
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Hackernews
Critical Unbound DNSSEC Validator Flaw Could Allow RCE via a Malicious DNS Zone
blogs_hackernews·2026-09-17·CVSS 9.8
CVE-2026-81642 [CRITICAL] Critical Unbound DNSSEC Validator Flaw Could Allow RCE via a Malicious DNS Zone
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## Critical Unbound DNSSEC Validator Flaw Could Allow RCE via a Malicious DNS Zone
Every release of the Unbound DNS resolver before 1.26.1 has a critical heap overflow in its DNSSEC validator, maintainer NLnet Labs said in an advisory on Wednesday.
An attacker who controls a malicious zone and queries a vulnerable resolver can trigger it, enabling remote code execution.
Unbound 1.26.1, released the same day, fixes the bug, tracked as CVE-2026-81642 , along with eight other flaws. One of the eight, CVE-2026-82717 , is a heap corruption bug in CNAME synthesis reported by Ben Morris of Anthropic. It could also lead to remote code
2026-09-16
Published