CVE-2026-31664
What it is
In the Linux kernel, the following vulnerability has been resolved: xfrm: clear trailing padding in build_polexpire() build_expire() clears the trailing padding bytes of struct xfrm_user_expire after setting the hard field via memset_after(), but the analogous function build_polexpire() does not do this for struct xfrm_user_polexpire. The padding bytes after the __u8 hard field are left uninitialized from the heap allocation, and are then sent to userspace via netlink multicast to XFRMNLGRP_EXPIRE listeners, leaking kernel heap memory contents. Add the missing memset_after() call, matching build_expire().
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 6.1.169
- Linux Kernel < 6.6.135
- Linux Kernel < 6.12.82
- Linux Kernel < 6.18.23
- Linux Kernel < 6.19.13
- Linux Kernel 2.6.12
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31664.md and follow it. Check whether this project is affected by CVE-2026-31664. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0
- https://git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788e
- https://git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2
- https://git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4
- https://git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6
- https://git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37
References
- https://git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0
- https://git.kernel.org/stable/c/a5127501c8d30b5728791b1e340284ca5c9cc4bd
- https://git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788e
- https://git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2
- https://git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4
- https://git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6
- https://git.kernel.org/stable/c/e6f4ffe8596947a595c9544e73a73adcb0568b88
- https://git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html