CVE-2026-72326: Linux kernel · net/sched: cake: reject overhead values that underflow length
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% 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 +41
Exploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 corrects this vulnerability by clamping negative adjusted packet lengths before link-layer framing adjustments in the CAKE scheduler. Users should apply the official Linux kernel updates that include this fix. No additional mitigation is required beyond applying the patch.
Description
A vulnerability in the Linux kernel's CAKE network scheduler allows signed overhead values to underflow the packet length calculation, causing a negative effective length to wrap to a large unsigned value. This flaw affects rate accounting by relying on integer wraparound rather than the intended packet size. The issue has been resolved by clamping negative adjusted lengths before link-layer framing adjustments.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72326 (opens in a new tab)
- git.kernel.org/stable/c/297f459865360b46a887667cbf3aac6a6f013841 (opens in a new tab)
- git.kernel.org/stable/c/336c1e414fc0e9844d445174e8ada2a7dd8d1c4b (opens in a new tab)
- git.kernel.org/stable/c/7aa0e64fea778a9e3df73e64da95367ff8ad2ea5 (opens in a new tab)
- git.kernel.org/stable/c/b7f97cae7ec1b6c3c32843c42be218690d310467 (opens in a new tab)
- git.kernel.org/stable/c/bcdf3a3664f7d2c4e37e155f30f72ef33f041804 (opens in a new tab)
- git.kernel.org/stable/c/e1df6cff03aad8c96e55a8b2a991e505c7a3ff6f (opens in a new tab)
- git.kernel.org/stable/c/f1e7807df5bf2d42a40266430e9f82f37633cdcf (opens in a new tab)
- git.kernel.org/stable/c/f511dd7bf6077aa7afbe72914520553fedaacbb4 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72326 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72326 (opens in a new tab)
- git.kernel.org/linus/b7f97cae7ec1b6c3c32843c42be218690d310467 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)