Linux: Use After Free
CVE-2026-43153 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 dfb3474230d392f809359f15aeaa9be4b1798199, 759e44a6cba8e81d945ffc269a326ec39e7f54f5, 2fbc8421d1db102c0e5458607e042a23a03648b1 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 0.18% 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 dfb3474230d392f809359f15aeaa9be4b1798199 or 759e44a6cba8e81d945ffc269a326ec39e7f54f5 or 2fbc8421d1db102c0e5458607e042a23a03648b1 or 457121c01f609b9934addbb04d5c1ef638c71c61, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.75 or 6.18.16 or 6.19.6, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, dfb3474230d392f809359f15aeaa9be4b1798199; 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, 759e44a6cba8e81d945ffc269a326ec39e7f54f5; 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, 2fbc8421d1db102c0e5458607e042a23a03648b1; 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, 457121c01f609b9934addbb04d5c1ef638c71c61; 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, 530082df991903f3330354e99e0cb7b05debfa86; 07120f1abdff80f3d1351f733661abe28d609535 up to, but not including, 3a65ea768b8094e4699e72f9ab420eb9e0f3f568; 5.9 | dfb3474230d392f809359f15aeaa9be4b1798199, 759e44a6cba8e81d945ffc269a326ec39e7f54f5, 2fbc8421d1db102c0e5458607e042a23a03648b1, 457121c01f609b9934addbb04d5c1ef638c71c61, 530082df991903f3330354e99e0cb7b05debfa86, 3a65ea768b8094e4699e72f9ab420eb9e0f3f568 |
| Linux | Linux Kernel | 5.9 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.16; 6.19 up to, but not including, 6.19.6 | 6.12.75, 6.18.16, 6.19.6 |
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 CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: xfs: remove xfs_attr_leaf_hasname The calling convention of xfs_attr_leaf_hasname() is problematic, because it returns a NULL buffer when xfs_attr3_leaf_read fails, a valid buffer when xfs_attr3_leaf_lookup_int returns -ENOATTR or -EEXIST, and a non-NULL buffer pointer for an already released buffer when xfs_attr3_leaf_lookup_int fails with other error values. Fix this by simply open coding xfs_attr_leaf_hasname in the callers, so that the buffer release code is done by each caller of xfs_attr3_leaf_read.
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
Other references
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.3 High severity
- 8.8 High severity
- 8.8 High severity
- 8.3 High severity
Spotted an error? Tell us.