CVE-2026-31696

Kernel warning via unchecked RxRPC ticket length

Published May 1, 2026 · Updated May 1, 2026

Improper input validation in the RxRPC key parser in Linux Kernel allows local users to trigger a kernel warning via a crafted key. The non-XDR path in rxrpc_preparse accepts an oversized ticket length, causing rxrpc_read to calculate a token size beyond AFSTOKEN_LENGTH_MAX. Unprivileged local access is required; the documented consequence is a WARN_ON rather than a confirmed privilege gain or unconditional system crash.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in the RxRPC key parser in Linux Kernel allows local users to trigger a kernel warning via a crafted key. The non-XDR path in rxrpc_preparse accepts an oversized ticket length, causing rxrpc_read to calculate a token size beyond AFSTOKEN_LENGTH_MAX. Unprivileged local access is required; the documented consequence is a WARN_ON rather than a confirmed privilege gain or unconditional system crash.

The record

CVE
CVE-2026-31696
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.17
  2. Affected versionversion=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <1fa36cf495b0023e8475d038535c05e4063211e1
  3. Affected versionversion=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <4458757c020592a3094366e0fb20457383b42f92
  4. Affected versionversion=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <a1be1c9ece26cea69654f28b255ff9a7906b897b
  5. Affected versionversion=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <ac33733b10b484d666f97688561670afd5861383
  6. Affected versionversion=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <ce383ba615339f8eaec646a166d2c2b015bb5ca0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.17; version=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <1fa36cf495b0023e8475d038535c05e4063211e1; version=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <4458757c020592a3094366e0fb20457383b42f92; version=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <a1be1c9ece26cea69654f28b255ff9a7906b897b; version=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <ac33733b10b484d666f97688561670afd5861383; version=8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 <ce383ba615339f8eaec646a166d2c2b015bb5ca0

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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