Back to CVE records
Medium 5.5Published Apr 24, 2026

CVE-2026-31664xfrm: clear trailing padding in build_polexpire()

Updated under an hour ago ()

Does this affect you?

It affects Linux and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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().

CVSS
5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
Not given
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Linux
NVD analysis
Modified
Record last updated
Oct 15, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Linux Linux
linux:linux (from the name)
from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before a5127501c8d30b5728791b1e340284ca5c9cc4bd; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before e6f4ffe8596947a595c9544e73a73adcb0568b88; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before ac6985903db047eaff54db929e4bf6b06782788e; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before c221ed63a2769a0af8bd849dfe25740048f34ef4; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before eda30846ea54f8ed218468e5480c8305ca645e37; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before b1dfd6b27df35ef4f87825aa5f607378d23ff0f2; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before e1af65c669ebb1666c54576614c01a7f9ffcfff6; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 71a98248c63c535eaa4d4c22f099b68d902006d0
CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)
from V3.1.6
CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)
from V3.1.6
CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)
from V3.1.6
CISA ADP
linux linux_kernel
linux:linux_kernel
from 2.6.12.1 before 6.1.169; from 6.2 before 6.6.135; from 6.7 before 6.12.82; from 6.13 before 6.18.23; from 6.19 before 6.19.13; 2.6.12; 2.6.12; 2.6.12; and 9 more ranges
NVD

References

  • patch
  • patch
  • patch
  • patch
  • patch
  • patch

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

Your cookie choices
We use essential cookies to run this site, and, only with your consent, an advertising cookie from Google to measure whether our ads lead to sign-ups and subscriptions. See our for details.