Linux: Use After Free
CVE-2026-31454 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 edd1637d4e3911ab6c760f553f2040fe72f61a13, 19437e4f7bb909afde832b39372aa2f3ce3cfd88, 6dbe17f19c290a72ce57d5abc70e1fad0c3e14e5 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 edd1637d4e3911ab6c760f553f2040fe72f61a13 or 19437e4f7bb909afde832b39372aa2f3ce3cfd88 or 6dbe17f19c290a72ce57d5abc70e1fad0c3e14e5 or 75669e987137f49c99ca44406bf0200d1892dd16, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.131, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, edd1637d4e3911ab6c760f553f2040fe72f61a13; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 19437e4f7bb909afde832b39372aa2f3ce3cfd88; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 6dbe17f19c290a72ce57d5abc70e1fad0c3e14e5; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 75669e987137f49c99ca44406bf0200d1892dd16; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, d8fc60bbaf5aea1604bf9f4ed565da6a1ac7a87d; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 50f5f056807b7bed74f4f307f2ca0ed92f3e556d; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 4c7d50147316cf049462f327c4a3e9dc2b7f1dd0; 90c60e16401248a4900f3f9387f563d0178dcf34 up to, but not including, 394d70b86fae9fe865e7e6d9540b7696f73aa9b6; and 1 more ranges | edd1637d4e3911ab6c760f553f2040fe72f61a13, 19437e4f7bb909afde832b39372aa2f3ce3cfd88, 6dbe17f19c290a72ce57d5abc70e1fad0c3e14e5, 75669e987137f49c99ca44406bf0200d1892dd16, d8fc60bbaf5aea1604bf9f4ed565da6a1ac7a87d, 50f5f056807b7bed74f4f307f2ca0ed92f3e556d |
| Linux | Linux Kernel | 5.9 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.131; 6.7 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 | 5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80, 6.18.21 |
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: save ailp before dropping the AIL lock in push callbacks In xfs_inode_item_push() and xfs_qm_dquot_logitem_push(), the AIL lock is dropped to perform buffer IO. Once the cluster buffer no longer protects the log item from reclaim, the log item may be freed by background reclaim or the dquot shrinker. The subsequent spin_lock() call dereferences lip->li_ailp, which is a use-after-free. Fix this by saving the ailp pointer in a local variable while the AIL lock is held and the log item is guaranteed to be valid.
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
- git.kernel.org/stable/c/19437e4f7bb909afde832b39372aa2f3ce3cfd88
- git.kernel.org/stable/c/394d70b86fae9fe865e7e6d9540b7696f73aa9b6
- git.kernel.org/stable/c/4c7d50147316cf049462f327c4a3e9dc2b7f1dd0
- git.kernel.org/stable/c/50f5f056807b7bed74f4f307f2ca0ed92f3e556d
- git.kernel.org/stable/c/6dbe17f19c290a72ce57d5abc70e1fad0c3e14e5
- git.kernel.org/stable/c/75669e987137f49c99ca44406bf0200d1892dd16
- git.kernel.org/stable/c/d8fc60bbaf5aea1604bf9f4ed565da6a1ac7a87d
- git.kernel.org/stable/c/edd1637d4e3911ab6c760f553f2040fe72f61a13
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
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