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VulnerabilityPublished Updated

CVE-2026-31676: Linux kernel · rxrpc: only handle RESPONSE during service challenge

Affects Linux kernelSource GCVE Database

0
Authoritative record:CVE-2026-31676· High 7.5

Not known to be exploited · CVSS 7.5 High · fixed in 6.8.0-1057.60~22.04.1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1057.60~22.04.1, 6.8.0-1059.65~22.04.1, 6.8.0-1060.63~22.04.1 +42
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Apr 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 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1008.8
4 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-nvidiapkg:deb/ubuntu/linux-nvidia@7.0.0-1006.6?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1006.6
Fixed in
  • 7.0.0-1006.6
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-35.35?arch=source&distro=questingOther threatsAffected
  • <6.17.0-35.35
Fixed in
  • 6.17.0-35.35
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1017.17?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1017.17
Fixed in
  • 6.17.0-1017.17
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1017.17?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1017.17
Fixed in
  • 6.17.0-1017.17
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–

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

AI-suggested

An official patch is available and should be applied to affected Linux kernel versions to remediate this vulnerability. The vendor advisory from Ubuntu confirms the fix has been released. No additional mitigation steps are required beyond applying the update.

Description

A vulnerability in the Linux kernel's RxRPC networking subsystem was resolved by restricting processing of RESPONSE packets to the service challenge state. This fix prevents duplicate or late RESPONSE packets from re-triggering the setup process, which could lead to unstable behavior. The issue affects specific Linux kernel versions and has a CVSS score of 7.5, indicating a medium severity with potential impact on availability. A patch is available to address this vulnerability.

References

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