Linux kernel percpu array map replacement skips max_entries check
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: 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.10 before 7.1 is affected. The generic map metadata comparison used for percpu array maps does not compare max_entries, so a percpu array inner map can be replaced with a smaller one. A local attacker with low privileges can then cause out-of-bounds memory access in the kernel, which can lead to high confidentiality, integrity and availability impact.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: bpf: Use array_map_meta_equal for percpu array inner map replacement percpu_array_map_ops.map_meta_equal points to the generic bpf_map_meta_equal(), which does not compare max_entries. When a percpu array serves as an inner map, replacing it with one that has fewer max_entries bypasses the check. Since percpu_array_map_gen_lookup() inlines the original template's index_mask as a JIT immediate, a lookup on the replacement map can access pptrs[] out of bounds. Point percpu_array_map_ops.map_meta_equal to array_map_meta_equal(), which already enforces the max_entries equality check. Add a selftest to verify that replacing a percpu array inner map with a differently-sized one is rejected.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to version 7.1 or later. Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 and Red Hat OpenShift Container Platform 5 are listed as affected without a fix, and Red Hat gives no fix plan for them.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 5 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-09 Threatist record created from CVE-2026-98376
- 2026-10-09 Alias added: GHSA-69ch-wm32-w5g8
- 2026-10-11 Affected versions changed · Red Hat
- 2026-10-11 CVSS score added · Red Hat
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score changed · Red Hat
- 2026-10-24 CVSS score added · CNA
- 2026-11-06 Affected versions changed · Red Hat
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Sources
- CVE-2026-98376 · CVE Program
- CVE-2026-98376 · NVD
- FIRST EPSS
- GHSA-69ch-wm32-w5g8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98376 · Red Hat security data · CC BY 4.0
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