bpf: Guard conntrack opts error writes
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Guard conntrack opts error writes The conntrack lookup and allocation kfuncs take an opts pointer together with an opts__sz argument. The verifier checks only the memory range described by opts__sz, but the wrappers unconditionally write opts->error whenever the internal lookup or allocation helper returns an error. For an invalid size smaller than the end of opts->error, that write can land outside the verifier-checked range. Keep returning NULL for invalid arguments, but only report the error through opts->error when the supplied size includes the field. This preserves error reporting for the supported 12-byte and 16-byte layouts, and for other invalid sizes that still include opts->error.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72423
- 2026-10-03 Alias added: GHSA-x2j2-wxw5-pjr8
- 2026-10-16 Fix available: Linux/Linux@453f4f1e90de55b6bc297936031b68bef93f2e28, Linux/[email protected] · CNA
- 2026-10-16 1 new reference · CNA
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-21 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@63d95c6bbd6fc0e411404188306a1fea456300b0 +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@6fd973def4d6cb89aaf7e9b6bc26cac977f6da13 · CNA
- 2026-10-30 1 new reference · CNA
References
Other 6
- https://git.kernel.org/stable/c/6fd973def4d6cb89aaf7e9b6bc26cac977f6da13
- https://git.kernel.org/stable/c/669bc3b345712112d3f033a1953f5a10b15e7c65
- https://git.kernel.org/stable/c/63d95c6bbd6fc0e411404188306a1fea456300b0
- https://git.kernel.org/stable/c/453f4f1e90de55b6bc297936031b68bef93f2e28
- https://git.kernel.org/stable/c/dd74c80203842a21b2ebb9f70d1260d9aa20fa05
- https://git.kernel.org/stable/c/6f6183a39533d727deaa5061cadae6dd9e6744d0
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- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
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- 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
Sources
- CVE-2026-72423 · CVE Program
- CVE-2026-72423 · NVD
- FIRST EPSS
- GHSA-x2j2-wxw5-pjr8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-72423 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences