Linux kernel BPF sock context code yields out-of-range values
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel BPF sock context access code, from 5.8 before the fixed versions, loads the rx_queue_mapping field in a way that can leave upper bits set. For the special value -1 it uses a 64-bit move that sign-extends, so a BPF program can read a value above the range the verifier assumes.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_sock context code generation Currently, the ctx access code reads the rx_queue_mapping field with either a 4-byte or 2-byte load. The rest of the bits in the register are marked known zero by the verifier. However, the emitted ctx access code places in the register on certain the special value (-1) using BPF_MOV_IMM64, which gets sign-extended to turn on all the bits in the register. By shifting this value right, the program ends up with a value at runtime above what the verifier assumes is possible. Fix this by ensuring the read value is as wide as the assumed size. Use MOV32 instructions instead of MOV64 instructions to keep the upper bits zero as assumed by the verifier. Also properly report the size of the destination variable (the bpf_sock field, 4 bytes) instead of the source (the socket field, 2 bytes).
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3. Red Hat Enterprise Linux 6 has no fix planned, and Red Hat Enterprise Linux 8, 9 and 10 and OpenShift Container Platform 4 and 5 have no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3
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 |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98590
- 2026-10-18 Alias added: GHSA-6ffg-3w9m-mjpv
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-27 CVSS score changed · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/e3ddcf4aeb342d4de2e5761c7042270d454752de
- https://git.kernel.org/stable/c/4a41d064facc3330e176ecbbf5b0026ed18a5c69
- https://git.kernel.org/stable/c/70288599d1754e157df8326239316dbdf08ea33c
- https://git.kernel.org/stable/c/ea4dc96c902ccfa49dd3e4f23c443dab4a74b018
- https://git.kernel.org/stable/c/b3f37afc7fd7c52bc2114310aff1eb24c7cd4d73
- https://git.kernel.org/stable/c/d95dd5a6c6cd08d5ae466d3aed27b3cf59155a6c
- https://git.kernel.org/stable/c/84ebb991ae985149079ae9ab51b7e3ba25a9ff53
- https://git.kernel.org/stable/c/4a4852376e3a2727ea40e61143d6d7c22bb6dfad
More Linux vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel 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
Sources
- CVE-2026-98590 · CVE Program
- CVE-2026-98590 · NVD
- FIRST EPSS
- GHSA-6ffg-3w9m-mjpv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98590 · Red Hat security data · CC BY 4.0
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