CVE-2026-31624: Linux kernel · HID: core: clamp report_size in s32ton() to avoid undefined shift
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in eb415ddaf25e09ddb8fe5736a70c9de2e6462534 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:04 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in eb415ddaf25e09ddb8fe5736a70c9de2e6462534, ea363a34086ddb4231adc581a7f36c39ec154bfc, 97014719bb8fccb1ffcbbc299e84b1f11b114195 +6
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In 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.
References
- git.kernel.org/stable/c/76ad02854a30c394e0c076e6e6bed0a388573a94 (opens in a new tab)
- git.kernel.org/stable/c/eb415ddaf25e09ddb8fe5736a70c9de2e6462534 (opens in a new tab)
- git.kernel.org/stable/c/0ab048dbdb1daacf17d52e9252297eb6e1298e49 (opens in a new tab)
- git.kernel.org/stable/c/932ae5309e53561197aa7d1606c7cf63af10e24f (opens in a new tab)
- git.kernel.org/stable/c/58386f00af710922cafb0fb69211497beddfaa95 (opens in a new tab)
- git.kernel.org/stable/c/8a8333237f1f5caab8d4c3d2c2e7578c4263a97f (opens in a new tab)
- git.kernel.org/stable/c/ea363a34086ddb4231adc581a7f36c39ec154bfc (opens in a new tab)
- git.kernel.org/stable/c/97014719bb8fccb1ffcbbc299e84b1f11b114195 (opens in a new tab)
- git.kernel.org/stable/c/69c02ffde6ed4d535fa4e693a9e572729cad3d0d (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)