Linux: Use After Free
CVE-2026-43063 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 unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions b5c5a50c2f513d4a13a6763564a07b470e69cc5a, a1a5df1038f0b3c560d204270373621a4e622808, 40082d08b638485cbaa543dc8087a3d1844d6f08 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 0.13% 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 b5c5a50c2f513d4a13a6763564a07b470e69cc5a or a1a5df1038f0b3c560d204270373621a4e622808 or 40082d08b638485cbaa543dc8087a3d1844d6f08 or 70685c291ef82269180758130394ecdc4496b52c, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.80 or 6.18.21 or 6.19.11, whichever matches your release line, or a later version.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ae673f534a30976ce5e709c4535a59c12b786ef3 up to, but not including, b5c5a50c2f513d4a13a6763564a07b470e69cc5a; ae673f534a30976ce5e709c4535a59c12b786ef3 up to, but not including, a1a5df1038f0b3c560d204270373621a4e622808; ae673f534a30976ce5e709c4535a59c12b786ef3 up to, but not including, 40082d08b638485cbaa543dc8087a3d1844d6f08; ae673f534a30976ce5e709c4535a59c12b786ef3 up to, but not including, 70685c291ef82269180758130394ecdc4496b52c; 6.10 | b5c5a50c2f513d4a13a6763564a07b470e69cc5a, a1a5df1038f0b3c560d204270373621a4e622808, 40082d08b638485cbaa543dc8087a3d1844d6f08, 70685c291ef82269180758130394ecdc4496b52c |
| Linux | Linux Kernel | 6.10 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 7.0 | 6.12.80, 6.18.21, 6.19.11 |
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
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: xfs: don't irele after failing to iget in xfs_attri_recover_work xlog_recovery_iget* never set @ip to a valid pointer if they return an error, so this irele will walk off a dangling pointer. Fix that.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 8.1 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.1 High severity
- 8.1 High severity
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