Skip to main content
VulnerabilityPublished Updated

CVE-2026-80603: Linux kernel · netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 9.1 Critical · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
9.1Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +40
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-38.38
Fixed in
  • 7.0.0-38.38
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1017.17
Fixed in
  • 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1016.16
Fixed in
  • 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1008.9
Fixed in
  • 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available that corrects the loop condition in parse_dcc() to prevent the out-of-bounds read. Users should apply the official Linux kernel updates that address this issue. The vendor advisory confirms the availability of fixes. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's netfilter nf_conntrack_irc module was fixed. The flaw is an off-by-one out-of-bounds read in the parse_dcc() function, where the code incorrectly treats an exclusive end pointer as inclusive, potentially causing a read of uninitialized memory. This can lead to incorrect parsing of DCC IP or port values. The issue was addressed by correcting the loop condition to use a strict less-than comparison consistent with the caller's convention.

References

Community reviews

Loading reviews…