CVE-2026-31420: Linux kernel · bridge: mrp: reject zero test interval to avoid OOM panic
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1064.67~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1064.67~22.04.1, 6.8.0-1067.75~22.04.1, 6.8.0-1065.72~22.04.1 +27
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-nvidiapkg:deb/ubuntu/linux-nvidia?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
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 enforces a minimum test interval value of 1 for the affected netlink attributes, preventing zero from being accepted and thus avoiding the tight loop and memory exhaustion. Users should apply the official kernel update that includes this fix. Since patchAvailable is true, remediation via official fix is possible and recommended.
Description
A vulnerability in the Linux kernel bridge MRP subsystem allowed a zero test interval value to be accepted without validation, causing a tight loop that exhausts system memory and triggers a kernel panic due to an out-of-memory deadlock. This issue was fixed by enforcing a minimum interval value of 1 at the netlink attribute parsing layer, preventing zero from reaching the workqueue scheduling code.
References
- ubuntu.com/security/CVE-2026-31420 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-31420 (opens in a new tab)
- git.kernel.org/linus/fa6e24963342de4370e3a3c9af41e38277b74cf3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8793-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8802-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8793-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8906-1 (opens in a new tab)