CVE-2026-31624
MediumIn the Linux kernel, the following vulnerability has been resolved: HID: core: clamp report_size in s32ton() to avoid undefined shift s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
2.6.20
and later are affected. Fixed in
5.10.258,
5.15.209,
6.1.175,
6.6.136,
6.12.83,
6.18.24,
6.19.14,
7.0.1,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-31624 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0ab048dbdb1daacf17d52e9252297eb6e1298e49
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PatchKernel patch commithttps://git.kernel.org/stable/c/58386f00af710922cafb0fb69211497beddfaa95
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PatchKernel patch commithttps://git.kernel.org/stable/c/69c02ffde6ed4d535fa4e693a9e572729cad3d0d
Frequently asked questions
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What is CVE-2026-31624?
CVE-2026-31624 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.20 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31624 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-31624?
CVE-2026-31624 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-31624?
Yes — CVE-2026-31624 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 2.6.20 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31624 actively exploited?
No — CVE-2026-31624 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.