CVE-2026-43341: Linux kernel · net/ipv6: ioam6: prevent schema length wraparound in trace fill
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1111.118~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1111.118~20.04.1, 5.15.0-1116.125~20.04.1, 5.15.0-1111.121~20.04.1 +78
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 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-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | 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– |
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 and should be applied. The Ubuntu security advisory USN-8490-1 confirms that this and other kernel vulnerabilities have been fixed in updated kernel packages. Users should update to the fixed kernel versions and reboot their systems. Due to ABI changes, third-party kernel modules must be recompiled and reinstalled after the update.
Description
A vulnerability in the Linux kernel's IPv6 ioam6 tracing subsystem allows a schema length wraparound that leads to a trace buffer overflow. This occurs because the schema length is stored in an 8-bit unsigned integer, causing it to wrap from 256 to 0 under certain conditions, bypassing buffer space checks and resulting in memory corruption. The issue has been resolved by changing the schema length storage to an unsigned int to prevent wraparound and ensure proper buffer boundary checks.
References
- ubuntu.com/security/CVE-2026-43341 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43341 (opens in a new tab)
- git.kernel.org/linus/5e67ba9bb531e1ec6599a82a065dea9040b9ce50 (opens in a new tab)
- git.kernel.org/stable/c/184d2e9db27c0f76226b5cad16fe29510a5d2280 (opens in a new tab)
- git.kernel.org/stable/c/5e67ba9bb531e1ec6599a82a065dea9040b9ce50 (opens in a new tab)
- git.kernel.org/stable/c/77695a69baca9b99d95fad09fc78c2318736604f (opens in a new tab)
- git.kernel.org/stable/c/d1b041080086e91d3733a5438a8c51ad5d3d8e09 (opens in a new tab)
- git.kernel.org/stable/c/d6e1c9b02d85a4f1f4ba6d68e916d9b610a3ed7d (opens in a new tab)
- git.kernel.org/stable/c/e96d48b37708d53cbdc47f6f60b0714fc4a5f596 (opens in a new tab)
- ubuntu.com/security/notices/USN-8490-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8491-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8493-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8497-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8498-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8493-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8508-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-3 (opens in a new tab)