Linux: Use After Free
CVE-2026-46267 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions c60f41022eaad2a1dafecd3ae6f249a3bd6d4b6e, a24a676329d40481b2331bfa1418a679577dfd3a, 77eef9f2eef045c3c37a3df82d3e661afb866b98 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.12% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to c60f41022eaad2a1dafecd3ae6f249a3bd6d4b6e or a24a676329d40481b2331bfa1418a679577dfd3a or 77eef9f2eef045c3c37a3df82d3e661afb866b98 or cf70cedce327833296ebe6043364d1e44b76a2ab, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.202 or 6.1.165 or 6.6.128 or 6.12.75, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, c60f41022eaad2a1dafecd3ae6f249a3bd6d4b6e; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, a24a676329d40481b2331bfa1418a679577dfd3a; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, 77eef9f2eef045c3c37a3df82d3e661afb866b98; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, cf70cedce327833296ebe6043364d1e44b76a2ab; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, 276820278e9717cc7d4bb32381892dd3ddf418d4; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, 1cb97b1225450af3f7b728777929ba50c6a58ced; 4a61cd6687fc6348d08724676d34e38160d6cf9b up to, but not including, c9efde1e537baed7648a94022b43836a348a074f; 3.7 | c60f41022eaad2a1dafecd3ae6f249a3bd6d4b6e, a24a676329d40481b2331bfa1418a679577dfd3a, 77eef9f2eef045c3c37a3df82d3e661afb866b98, cf70cedce327833296ebe6043364d1e44b76a2ab, 276820278e9717cc7d4bb32381892dd3ddf418d4, 1cb97b1225450af3f7b728777929ba50c6a58ced |
| Linux | Linux Kernel | 3.7 up to, but not including, 5.15.202; 5.16 up to, but not including, 6.1.165; 6.2 up to, but not including, 6.6.128; 6.7 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4 | 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: nfc: hci: shdlc: Stop timers and work before freeing context llc_shdlc_deinit() purges SHDLC skb queues and frees the llc_shdlc structure while its timers and state machine work may still be active. Timer callbacks can schedule sm_work, and sm_work accesses SHDLC state and the skb queues. If teardown happens in parallel with a queued/running work item, it can lead to UAF and other shutdown races. Stop all SHDLC timers and cancel sm_work synchronously before purging the queues and freeing the context. Found by Linux Verification Center (linuxtesting.org) with SVACE.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/1cb97b1225450af3f7b728777929ba50c6a58ced
- git.kernel.org/stable/c/276820278e9717cc7d4bb32381892dd3ddf418d4
- git.kernel.org/stable/c/77eef9f2eef045c3c37a3df82d3e661afb866b98
- git.kernel.org/stable/c/a24a676329d40481b2331bfa1418a679577dfd3a
- git.kernel.org/stable/c/c60f41022eaad2a1dafecd3ae6f249a3bd6d4b6e
- git.kernel.org/stable/c/c9efde1e537baed7648a94022b43836a348a074f
- git.kernel.org/stable/c/cf70cedce327833296ebe6043364d1e44b76a2ab
Recent Use After Free vulnerabilities
- 8.4 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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