CVE-2026-31633: Linux kernel · rxrpc: Fix integer overflow in rxgk_verify_response()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in c1e242beb6b1efc3c286f617e8d940c8fbf2ed41 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:45 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in c1e242beb6b1efc3c286f617e8d940c8fbf2ed41, 699e52180f4231c257821c037ed5c99d5eb0edb8, 1f864d9daaf622aeaa774404fd51e7d6a435b046
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade Linux kernel to c1e242beb6b1efc3c286f617e8d940c8fbf2ed41, 699e52180f4231c257821c037ed5c99d5eb0edb8 or 1f864d9daaf622aeaa774404fd51e7d6a435b046.
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– |
AI-suggested
A fix for this vulnerability has been implemented and is available in the Linux kernel. Users and administrators should update to the fixed kernel versions identified by the commits c1e242beb6b1efc3c286f617e8d940c8fbf2ed41, 699e52180f4231c257821c037ed5c99d5eb0edb8, and 1f864d9daaf622aeaa774404fd51e7d6a435b046. Applying these updates will remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-31633 is a critical integer overflow vulnerability in the Linux kernel's rxrpc component, specifically in the rxgk_verify_response() function. The flaw arises from rounding up the token length before validating it, which allows bypassing the length check. This vulnerability has been fixed by adding a check against the unrounded token length to ensure the response fits within a single UDP packet.