xfrm: clear trailing padding in build_polexpire()
Priority LOW 24Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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().
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0012 1st percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.258, 5.15.209, 6.1.169 +5Red Hat: 5 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.12 and later | 5.10.258, 5.15.209, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.12 and later Fixed in 5.10.258, 5.15.209, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13, 7.0 Patch available CNA
CPE configurations NVD · 13
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 2.6.12.1 to before 6.1.169; 6.2 to before 6.6.135; 6.7 to before 6.12.82; 6.13 to before 6.18.23; 6.19 to before 6.19.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* | 2.6.12 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* | 2.6.12 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* | 2.6.12 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* | 2.6.12 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* | 2.6.12 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* | 7.0 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* | 7.0 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* | 7.0 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* | 7.0 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.12.1 to before 6.1.169; 6.2 to before 6.6.135; 6.7 to before 6.12.82; 6.13 to before 6.18.23; 6.19 to before 6.19.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* Versions 2.6.12 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* Versions 2.6.12 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* Versions 2.6.12 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* Versions 2.6.12 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* Versions 2.6.12 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* Versions 7.0 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* Versions 7.0 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13, 7.0
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31664
- 2026-10-03 Alias added: GHSA-5fvv-6wpc-9mr7
- 2026-11-06 CISA SSVC decision points changed
References
Patch 6
- https://git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788e
- https://git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4
- https://git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37
- https://git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2
- https://git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6
- https://git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0
More Linux Kernel vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-31664 · CVE Program
- CVE-2026-31664 · NVD
- FIRST EPSS
- GHSA-5fvv-6wpc-9mr7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-31664 · Red Hat security data · CC BY 4.0
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