Linux: Use After Free
CVE-2026-53270 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 d10730a1f2caf08088e0db1b19b242f3e6fa5f06, e4feec3174036ba772006be74beee0efa09a9eb8, 7d4f5004511757e3984901ffb412fcf858d80ed5 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 0.16% 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 d10730a1f2caf08088e0db1b19b242f3e6fa5f06 or e4feec3174036ba772006be74beee0efa09a9eb8 or 7d4f5004511757e3984901ffb412fcf858d80ed5 or c6376b9b1b4d2bad638256b1b3588e073344ae69, whichever matches your release line, or a later version.
- Update Linux Kernel to 3.19 or 4.2 or 5.10.259 or 5.15.210, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, d10730a1f2caf08088e0db1b19b242f3e6fa5f06; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, e4feec3174036ba772006be74beee0efa09a9eb8; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, 7d4f5004511757e3984901ffb412fcf858d80ed5; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, c6376b9b1b4d2bad638256b1b3588e073344ae69; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, 14e4689c113b4c06af1069364ade24fdd7055f33; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, 25918720ba97f974a4f8d433b5a0132c5b43f6f3; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, 19a9493faa4bf3c7bd0a386f30b60b1bb4a3da03; 05f00505a89acd21f5d0d20f5797dfbc4cf85243 up to, but not including, 193989cc6d80dd8e0460fb3992e69fa03bf0ff9b; and 5 more ranges | d10730a1f2caf08088e0db1b19b242f3e6fa5f06, e4feec3174036ba772006be74beee0efa09a9eb8, 7d4f5004511757e3984901ffb412fcf858d80ed5, c6376b9b1b4d2bad638256b1b3588e073344ae69, 14e4689c113b4c06af1069364ade24fdd7055f33, 25918720ba97f974a4f8d433b5a0132c5b43f6f3 |
| Linux | Linux Kernel | 3.18.23 up to, but not including, 3.19; 4.1.11 up to, but not including, 4.2; 4.2.1 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; and 3 more ranges | 3.19, 4.2, 5.10.259, 5.15.210, 6.1.176, 6.6.143 |
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: ipvs: clear the svc scheduler ptr early on edit ip_vs_edit_service() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->sched_data is already freed after RCU grace period. Fix it by clearing the ptr early in ip_vs_unbind_scheduler(), before the done_service method schedules any RCU callbacks. Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code.
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/14e4689c113b4c06af1069364ade24fdd7055f33
- git.kernel.org/stable/c/193989cc6d80dd8e0460fb3992e69fa03bf0ff9b
- git.kernel.org/stable/c/19a9493faa4bf3c7bd0a386f30b60b1bb4a3da03
- git.kernel.org/stable/c/25918720ba97f974a4f8d433b5a0132c5b43f6f3
- git.kernel.org/stable/c/7d4f5004511757e3984901ffb412fcf858d80ed5
- git.kernel.org/stable/c/c6376b9b1b4d2bad638256b1b3588e073344ae69
- git.kernel.org/stable/c/d10730a1f2caf08088e0db1b19b242f3e6fa5f06
- git.kernel.org/stable/c/e4feec3174036ba772006be74beee0efa09a9eb8
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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