Medium severity5.5NVD Advisory· Published Apr 24, 2026· Updated Jul 14, 2026
CVE-2026-31664
CVE-2026-31664
Description
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().
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
36cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*+ 13 more
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*range: >=2.6.12.1,<6.1.169
- cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
- (no CPE)
- osv-coords22 versionspkg:linux/kernelpkg:rpm/opensuse/dtb-aarch64&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-64kb&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-azure&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-default&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-default-base&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-docs&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-kvmsmall&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-obs-build&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-obs-qa&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-rt&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-source&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-syms&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-zfcpdump&distro=openSUSE%20Leap%2016.0pkg:rpm/suse/kernel-default&distro=SUSE%20Linux%20Enterprise%20Live%20Patching%2012%20SP5pkg:rpm/suse/kernel-default&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP5-LTSSpkg:rpm/suse/kernel-default&distro=SUSE%20Linux%20Enterprise%20Server%20LTSS%20Extended%20Security%2012%20SP5pkg:rpm/suse/kernel-source&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP5-LTSSpkg:rpm/suse/kernel-source&distro=SUSE%20Linux%20Enterprise%20Server%20LTSS%20Extended%20Security%2012%20SP5pkg:rpm/suse/kernel-syms&distro=SUSE%20Linux%20Enterprise%20Server%2012%20SP5-LTSSpkg:rpm/suse/kernel-syms&distro=SUSE%20Linux%20Enterprise%20Server%20LTSS%20Extended%20Security%2012%20SP5pkg:rpm/suse/kgraft-patch-SLE12-SP5_Update_84&distro=SUSE%20Linux%20Enterprise%20Live%20Patching%2012%20SP5
>= 2.6.12, < 5.10.258+ 21 more
- (no CPE)range: >= 2.6.12, < 5.10.258
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1.160000.2.17
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 6.12.0-160000.36.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 4.12.14-122.317.1
- (no CPE)range: < 1-8.7.1
Patches
Vulnerability mechanics
References
10- git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0nvdPatch
- git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788envdPatch
- git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2nvdPatch
- git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4nvdPatch
- git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6nvdPatch
- git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37nvdPatch
- cert-portal.siemens.com/productcert/html/ssa-019113.htmlnvd
- cert-portal.siemens.com/productcert/html/ssa-082556.htmlnvd
- git.kernel.org/stable/c/a5127501c8d30b5728791b1e340284ca5c9cc4bdnvd
- git.kernel.org/stable/c/e6f4ffe8596947a595c9544e73a73adcb0568b88nvd
News mentions
1- Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFPCISA ICS Advisories