CVE-2026-31499

Service hang via L2CAP teardown deadlock

Published Apr 22, 2026 · Updated Apr 22, 2026

Improper locking in Linux Kernel Bluetooth L2CAP allows local users to hang the system during connection teardown. In l2cap_conn_del(), synchronous cancellation of info_timer and id_addr_timer occurs while conn->lock is held, while both delayed-work callbacks acquire the same lock. Triggering requires local low-privileged access and a timing overlap between teardown and either delayed work item; the bounded impact is loss of availability.

CVSS severity5.5
Medium
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in Linux Kernel Bluetooth L2CAP allows local users to hang the system during connection teardown. In l2cap_conn_del(), synchronous cancellation of info_timer and id_addr_timer occurs while conn->lock is held, while both delayed-work callbacks acquire the same lock. Triggering requires local low-privileged access and a timing overlap between teardown and either delayed work item; the bounded impact is loss of availability.

The record

CVE
CVE-2026-31499
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 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=18ab6b6078fa8191ca30a3065d57bf35d5635761
  2. Affected versionversion=6.14
  3. Affected versionversion=ab4eedb790cae44313759b50fe47da285e2519d5 <00fdebbbc557a2fc21321ff2eaa22fd70c078608
  4. Affected versionversion=ab4eedb790cae44313759b50fe47da285e2519d5 <3f26ecbd9cde621dd94be7ef252c7210b965a5c7
  5. Affected versionversion=ab4eedb790cae44313759b50fe47da285e2519d5 <d008460de352e534f6721de829b093368564ec66
  6. Affected versionversion=efc30877bd4bc85fefe98d80af60fafc86e5775e
  7. Affected versionversion=f87271d21dd4ee83857ca11b94e7b4952749bbae

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=18ab6b6078fa8191ca30a3065d57bf35d5635761; version=6.14; version=ab4eedb790cae44313759b50fe47da285e2519d5 <00fdebbbc557a2fc21321ff2eaa22fd70c078608; version=ab4eedb790cae44313759b50fe47da285e2519d5 <3f26ecbd9cde621dd94be7ef252c7210b965a5c7; version=ab4eedb790cae44313759b50fe47da285e2519d5 <d008460de352e534f6721de829b093368564ec66; version=efc30877bd4bc85fefe98d80af60fafc86e5775e; version=f87271d21dd4ee83857ca11b94e7b4952749bbae

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

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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-667Improper Locking
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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