Linux: Use After Free
CVE-2026-53232 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 18c7c311323b19a353c3042180982e0ce5fa7e5f, 12fb84dc4dc8eb47ebe2b27f7de6255a4a205e1b, 9326b654f90a09eadeb796c82801a5609d57f0c8 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 0.26% 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 18c7c311323b19a353c3042180982e0ce5fa7e5f or 12fb84dc4dc8eb47ebe2b27f7de6255a4a205e1b or 9326b654f90a09eadeb796c82801a5609d57f0c8 or 3a254779c169954fe23328a1db51f67be374f913, whichever matches your release line, or a later version.
- Update Linux Kernel to 7.1 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 18c7c311323b19a353c3042180982e0ce5fa7e5f; 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 12fb84dc4dc8eb47ebe2b27f7de6255a4a205e1b; 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 9326b654f90a09eadeb796c82801a5609d57f0c8; 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 3a254779c169954fe23328a1db51f67be374f913; 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 0b27701ce93161d7bbf4b25fa20ca59963b0e20c; 298e54fa810e027f1b0800d789eb862592721f08 up to, but not including, 48774e87bbaa0056819d4b52301e4692e50e3252; 5.5 | 18c7c311323b19a353c3042180982e0ce5fa7e5f, 12fb84dc4dc8eb47ebe2b27f7de6255a4a205e1b, 9326b654f90a09eadeb796c82801a5609d57f0c8, 3a254779c169954fe23328a1db51f67be374f913, 0b27701ce93161d7bbf4b25fa20ca59963b0e20c, 48774e87bbaa0056819d4b52301e4692e50e3252 |
| Linux | Linux Kernel | 5.5 up to, but not including, 7.1; 7.1 | 7.1 |
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
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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:A/AC:L/PR:N/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: net: phy: clean the sfp upstream if phy probing fails Sashiko reported that we don't call sfp_bus_del_upstream() in the probe failure path, so let's add it, otherwise the sfp-bus is left with a dangling 'upstream' field, that may be used later on during SFP events. This issue existed before the generic phylib sfp support, back when drivers were calling phy_sfp_probe themselves.
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
- git.kernel.org/stable/c/0b27701ce93161d7bbf4b25fa20ca59963b0e20c
- git.kernel.org/stable/c/12fb84dc4dc8eb47ebe2b27f7de6255a4a205e1b
- git.kernel.org/stable/c/18c7c311323b19a353c3042180982e0ce5fa7e5f
- git.kernel.org/stable/c/3a254779c169954fe23328a1db51f67be374f913
- git.kernel.org/stable/c/9326b654f90a09eadeb796c82801a5609d57f0c8
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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