What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-22 · updated 2026-06-17

Description

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.

Affected products

• Linux kernel: from 5.12.1 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.131; from 6.7 before 6.12.80; from 6.13 before 6.18.21; from 6.19 before 6.19.11 — fixed in 5.15.203, 6.1.168, 6.12.80, 6.18.21, 6.19.11, 6.6.131

How to fix

Upgrade to a fixed version: Linux kernel 5.15.203, 6.1.168, 6.12.80, 6.18.21. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/1cb9c7bc9025c637564fabc7fcc3c9343949e310
• https://git.kernel.org/stable/c/3c3b97064764899c39a0abbd35a6caa031e70333
• https://git.kernel.org/stable/c/48b8814e25d073dd84daf990a879a820bad2bcbd
• https://git.kernel.org/stable/c/4d05dd18d867d58c6952a3bc260d244899da7256
• https://git.kernel.org/stable/c/7a5260fbc6e79a1595328ec5c6aa3f937504a1f0
• https://git.kernel.org/stable/c/87776f02449e3bded95b2ccbd6b012e9ae64e6f3
• https://git.kernel.org/stable/c/f8c444b918d639e1f9a621ee20fe481c1d10dfc4

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