Linux: Double Free
CVE-2026-53294 is a high-severity double 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 fc0089f82c3e36060c2c79156bc2018bfb16b56b, 5d4f3d0f64f1016cb78b400a70b67df91fac99b5, c494a11da45ad7ec9b0ff216c3e3ace351193bb6 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 fc0089f82c3e36060c2c79156bc2018bfb16b56b or 5d4f3d0f64f1016cb78b400a70b67df91fac99b5 or c494a11da45ad7ec9b0ff216c3e3ace351193bb6 or 3afca89fae501dbd7421e1777b5b8f033b1d98d0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, fc0089f82c3e36060c2c79156bc2018bfb16b56b; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 5d4f3d0f64f1016cb78b400a70b67df91fac99b5; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, c494a11da45ad7ec9b0ff216c3e3ace351193bb6; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 3afca89fae501dbd7421e1777b5b8f033b1d98d0; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 5c209299b0113e289e238fa5f2e8f00c59f76060; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 82f6dcea46cf5de65c4ba7283f7c7b34de4a324d; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 240c71a2aea36a1a4210f911a1c32ea88777e8e4; 8ea4484d0c2bb4e2152261943fa1a3522654b1c7 up to, but not including, 88ebadbf0deefdaccdab868b44ff70a0a257f473; and 1 more ranges | fc0089f82c3e36060c2c79156bc2018bfb16b56b, 5d4f3d0f64f1016cb78b400a70b67df91fac99b5, c494a11da45ad7ec9b0ff216c3e3ace351193bb6, 3afca89fae501dbd7421e1777b5b8f033b1d98d0, 5c209299b0113e289e238fa5f2e8f00c59f76060, 82f6dcea46cf5de65c4ba7283f7c7b34de4a324d |
| Linux | Linux Kernel | 4.4 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10; 7.1 | 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33 |
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: mailbox: mailbox-test: don't free the reused channel The RX channel can be aliased to the TX channel if it has a different MMIO. This special case needs to be handled when freeing the channels otherwise a double-free occurs.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
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
- git.kernel.org/stable/c/240c71a2aea36a1a4210f911a1c32ea88777e8e4
- git.kernel.org/stable/c/3afca89fae501dbd7421e1777b5b8f033b1d98d0
- git.kernel.org/stable/c/5c209299b0113e289e238fa5f2e8f00c59f76060
- git.kernel.org/stable/c/5d4f3d0f64f1016cb78b400a70b67df91fac99b5
- git.kernel.org/stable/c/82f6dcea46cf5de65c4ba7283f7c7b34de4a324d
- git.kernel.org/stable/c/88ebadbf0deefdaccdab868b44ff70a0a257f473
- git.kernel.org/stable/c/c494a11da45ad7ec9b0ff216c3e3ace351193bb6
- git.kernel.org/stable/c/fc0089f82c3e36060c2c79156bc2018bfb16b56b
Recent Double Free vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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