CVE-2026-31551

Local service interruption via concurrent debugfs writes

Published Apr 24, 2026 · Updated Apr 24, 2026

Integer underflow in Linux Kernel mac80211 allows local users to interrupt service through concurrent aql_enable debugfs writes. The aql_enable_write function checks aql_disable.key and later increments or decrements it without serializing concurrent writers, allowing its state to change between operations. Write access to the mac80211 debugfs control is required, and the bounded consequence is a kernel warning or soft lockup rather than data access.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Linux Kernel mac80211 allows local users to interrupt service through concurrent aql_enable debugfs writes. The aql_enable_write function checks aql_disable.key and later increments or decrements it without serializing concurrent writers, allowing its state to change between operations. Write access to the mac80211 debugfs control is required, and the bounded consequence is a kernel warning or soft lockup rather than data access.

The record

CVE
CVE-2026-31551
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-191, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 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=5.12
  2. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <256f7d4c11235d0569f78413c41dc89d2dc1557c
  3. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <29a1a350afcd28a2150bd73b8bd83eac3480f13e
  4. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <5ba05436f15d16ae7ab04b880e8bf8d440be892b
  5. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <787152497ac763deab16f6f4b7ce79aaeb3eb7e8
  6. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <8bb90ff77326c34e75b573b1febdd9586fec5aba
  7. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <b24763d32d5b4ada766deca4b42d6766272fef0c
  8. Affected versionversion=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <b94ae8e0d5fe1bdbbfdc3854ff6ce98f6876a828

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.12; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <256f7d4c11235d0569f78413c41dc89d2dc1557c; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <29a1a350afcd28a2150bd73b8bd83eac3480f13e; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <5ba05436f15d16ae7ab04b880e8bf8d440be892b; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <787152497ac763deab16f6f4b7ce79aaeb3eb7e8; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <8bb90ff77326c34e75b573b1febdd9586fec5aba; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <b24763d32d5b4ada766deca4b42d6766272fef0c; version=e908435e402aff23c9b0b3c59c7cd12b08b681b0 <b94ae8e0d5fe1bdbbfdc3854ff6ce98f6876a828

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-191Integer Underflow (Wrap or Wraparound)
T1499Endpoint Denial of Service

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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