Linux: Use After Free
CVE-2026-53272 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 5627e57f1da68ff0146896eb3d2eed25e62adc44, 59db5d8bcc65e04d8598afd81ec3a18edb407470, 86ab00cf81d44b675bb23db62b88fd76c8ac8cea 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 5627e57f1da68ff0146896eb3d2eed25e62adc44 or 59db5d8bcc65e04d8598afd81ec3a18edb407470 or 86ab00cf81d44b675bb23db62b88fd76c8ac8cea or 00bf6868df65fa95b3854996246d15759fdc7070, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.94 or 6.18.36 or 7.0.13, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 5627e57f1da68ff0146896eb3d2eed25e62adc44; 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 59db5d8bcc65e04d8598afd81ec3a18edb407470; 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 86ab00cf81d44b675bb23db62b88fd76c8ac8cea; 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 00bf6868df65fa95b3854996246d15759fdc7070; 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 95caf60da33d87ed26c28993620f0d92487b0296; 40452ffca3c1a0f2994e826f9fa213b107f1a2d4 up to, but not including, 1aee05e814d292064bf5fa15733741040cdc48ba; 5.17 | 5627e57f1da68ff0146896eb3d2eed25e62adc44, 59db5d8bcc65e04d8598afd81ec3a18edb407470, 86ab00cf81d44b675bb23db62b88fd76c8ac8cea, 00bf6868df65fa95b3854996246d15759fdc7070, 95caf60da33d87ed26c28993620f0d92487b0296, 1aee05e814d292064bf5fa15733741040cdc48ba |
| Linux | Linux Kernel | 5.17 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; 7.1 | 6.12.94, 6.18.36, 7.0.13 |
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: erofs: fix use-after-free on sbi->sync_decompress z_erofs_decompress_kickoff() can race with filesystem unmount, causing a use-after-free on sbi->sync_decompress. When I/O completes, z_erofs_endio() calls z_erofs_decompress_kickoff() to queue z_erofs_decompressqueue_work() asynchronously. Then, after all folios are unlocked, unmount workflow can proceed and sbi will be freed before accessing to sbi->sync_decompress. Thread (unmount) I/O completion kworker queue_work z_erofs_decompressqueue_work (all folios are unlocked) cleanup_mnt .. erofs_kill_sb erofs_sb_free kfree(sbi) access sbi->sync_decompress // UAF!!
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use After Free vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 8.2 High severity
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