# CVE-2026-31483: s390/syscalls: Add spectre boundary for syscall dispatch table

Status: published. Published: 2026-04-22. Updated: 2026-11-05.

In the Linux kernel, the following vulnerability has been resolved:

s390/syscalls: Add spectre boundary for syscall dispatch table

The s390 syscall number is directly controlled by userspace, but does
not have an array_index_nospec() boundary to prevent access past the
syscall function pointer tables.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 3c3b97064764899c39a0abbd35a6caa031e70333 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 1cb9c7bc9025c637564fabc7fcc3c9343949e310 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 7a5260fbc6e79a1595328ec5c6aa3f937504a1f0 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < f8c444b918d639e1f9a621ee20fe481c1d10dfc4 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 87776f02449e3bded95b2ccbd6b012e9ae64e6f3 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 4d05dd18d867d58c6952a3bc260d244899da7256 (affected, git); ≥ 56e62a73702836017564eaacd5212e4d0fa1c01d; < 48b8814e25d073dd84daf990a879a820bad2bcbd (affected, git). Source: CNA: Linux
- Linux / Linux: 5.12 (affected); ≥ 0; < 5.12 (unaffected, semver); ≥ 5.15.203; ≤ 5.15.* (unaffected, semver); ≥ 6.1.168; ≤ 6.1.* (unaffected, semver); ≥ 6.6.131; ≤ 6.6.* (unaffected, semver); ≥ 6.12.80; ≤ 6.12.* (unaffected, semver); ≥ 6.18.21; ≤ 6.18.* (unaffected, semver); ≥ 6.19.11; ≤ 6.19.* (unaffected, semver); ≥ 7.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-05; percentile 2.03%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/3c3b97064764899c39a0abbd35a6caa031e70333 (CNA: Linux)

- https://git.kernel.org/stable/c/1cb9c7bc9025c637564fabc7fcc3c9343949e310 (CNA: Linux)

- https://git.kernel.org/stable/c/7a5260fbc6e79a1595328ec5c6aa3f937504a1f0 (CNA: Linux)

- https://git.kernel.org/stable/c/f8c444b918d639e1f9a621ee20fe481c1d10dfc4 (CNA: Linux)

- https://git.kernel.org/stable/c/87776f02449e3bded95b2ccbd6b012e9ae64e6f3 (CNA: Linux)

- https://git.kernel.org/stable/c/4d05dd18d867d58c6952a3bc260d244899da7256 (CNA: Linux)

- https://git.kernel.org/stable/c/48b8814e25d073dd84daf990a879a820bad2bcbd (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-31483; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-31483; retrieved 2026-11-05; source updated Not reported

Revision: 8ae3217cd86be78b68404d1289ecbcbdd237ea29732635451178bd5648345d99

Canonical: https://y2.dev/cve/CVE-2026-31483

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- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.