CVE-2026-43089: Linux kernel · Memory Leak
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1112.119~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +64
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 6 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 fix is available and has been released by the vendor in updated Linux kernel packages. Users should apply the official Linux kernel security updates provided by their distribution, such as the Ubuntu security notice USN-8567-1. No additional mitigation actions are required beyond applying the patch.
Description
A vulnerability in the Linux kernel's xfrm_user component caused an information leak due to a one-byte padding hole in the struct xfrm_usersa_id. This padding was not zeroed before copying data to userspace, potentially leaking kernel memory contents. The issue has been fixed by zeroing the entire structure before setting its fields. The vulnerability has a medium severity with a CVSS score of 5.5 and does not impact confidentiality or integrity but affects availability. Multiple specific Linux kernel versions are affected. The vendor has released patches addressing this and other kernel vulnerabilities.
References
- ubuntu.com/security/CVE-2026-43089 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43089 (opens in a new tab)
- git.kernel.org/linus/1beb76b2053b68c491b78370794b8ff63c8f8c02 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8607-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8608-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8609-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8610-1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-43089 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- git.kernel.org/stable/c/1beb76b2053b68c491b78370794b8ff63c8f8c02 (opens in a new tab)
- git.kernel.org/stable/c/521385cbd50ca9474396d88462fcdfa6489685d9 (opens in a new tab)
- git.kernel.org/stable/c/5a1a4b049ddde41466ccac0daeec326254b133f2 (opens in a new tab)
- git.kernel.org/stable/c/700c9622b23c33b5933e6dcea816492c064e4e10 (opens in a new tab)
- git.kernel.org/stable/c/72a8de41c3eb4dcf22bf3b674ea38fb2f75d6f32 (opens in a new tab)
- git.kernel.org/stable/c/c2779ae9a3e5a044e5ccd564681511bbbcc5fc0f (opens in a new tab)
- git.kernel.org/stable/c/d3125c541a96fb3c0fc7210112684baf22b6c24d (opens in a new tab)
- git.kernel.org/stable/c/f779a6b6cdb6e12baa0663063ac59ab2a8f20c0c (opens in a new tab)