CVE-2025-39860

Kernel compromise via racy L2CAP socket cleanup

Published Sep 19, 2025 · Updated Sep 19, 2025

Use-after-free in Linux kernel Bluetooth L2CAP sockets allows local users to corrupt kernel memory through concurrent socket cleanup. l2cap_sock_release() calls l2cap_sock_cleanup_listen() without holding the socket lock, so two threads can dequeue and free the same child socket before a stale unlink touches it. An ordinary local user can race accept() and close() while an adjacent Bluetooth peer creates queued L2CAP children, enabling a kernel crash or privilege escalation.

CVSS severity8.0
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel Bluetooth L2CAP sockets allows local users to corrupt kernel memory through concurrent socket cleanup. l2cap_sock_release() calls l2cap_sock_cleanup_listen() without holding the socket lock, so two threads can dequeue and free the same child socket before a stale unlink touches it. An ordinary local user can race accept() and close() while an adjacent Bluetooth peer creates queued L2CAP children, enabling a kernel crash or privilege escalation.

The record

CVE
CVE-2025-39860
Published
Sep 19, 2025
Updated
Sep 19, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=06f87c96216bc5cd1094c23492274f77f1d5dd3b <83e1d9892ef51785cf0760b7681436760dda435a
  2. Affected versionversion=10426afe65c8bf7b24dd0c7be4dcc65f86fc99f9
  3. Affected versionversion=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <306b0991413b482dbf5585b423022123bb505966
  4. Affected versionversion=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <3dff390f55ccd9ce12e91233849769b5312180c2
  5. Affected versionversion=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <6077d16b5c0f65d571eee709de2f0541fb5ef0ca
  6. Affected versionversion=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <862c628108562d8c7a516a900034823b381d3cba
  7. Affected versionversion=29fac18499332211b2615ade356e2bd8b3269f98 <2ca99fc3512a8074de20ee52a87b492dfcc41a4d
  8. Affected versionversion=51822644a047eac2310fab0799b64e3430b5a111
  9. Affected versionversion=6.5
  10. Affected versionversion=82cdb2ccbe43337798393369f0ceb98699fe6037
  11. Affected versionversion=a2da00d1ea1abfb04f846638e210b5b5166e3c9c <964cbb198f9c46c2b2358cd1faffc04c1e8248cf
  12. Affected versionversion=fbe5a2fed8156cc19eb3b956602b0a1dd46a302d <47f6090bcf75c369695d21c3f179db8a56bbbd49

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=06f87c96216bc5cd1094c23492274f77f1d5dd3b <83e1d9892ef51785cf0760b7681436760dda435a; version=10426afe65c8bf7b24dd0c7be4dcc65f86fc99f9; version=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <306b0991413b482dbf5585b423022123bb505966; version=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <3dff390f55ccd9ce12e91233849769b5312180c2; version=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <6077d16b5c0f65d571eee709de2f0541fb5ef0ca; version=1728137b33c00d5a2b5110ed7aafb42e7c32e4a1 <862c628108562d8c7a516a900034823b381d3cba; version=29fac18499332211b2615ade356e2bd8b3269f98 <2ca99fc3512a8074de20ee52a87b492dfcc41a4d; version=51822644a047eac2310fab0799b64e3430b5a111; version=6.5; version=82cdb2ccbe43337798393369f0ceb98699fe6037; version=a2da00d1ea1abfb04f846638e210b5b5166e3c9c <964cbb198f9c46c2b2358cd1faffc04c1e8248cf; version=fbe5a2fed8156cc19eb3b956602b0a1dd46a302d <47f6090bcf75c369695d21c3f179db8a56bbbd49

Published CVSS scores

8.0Linux kernel CVE teamCVSS:3.1/AV:A/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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