Linux: Use After Free
CVE-2026-46212 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 1d4b241482d9025c537afb3c7c8419c72c0e0c82, a1a99837bb6169cfb9187abaa2005e8f12079426, b88c865dcf6e9f20bfe66a360d4b62941ef769b8 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 0.27% 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 1d4b241482d9025c537afb3c7c8419c72c0e0c82 or a1a99837bb6169cfb9187abaa2005e8f12079426 or b88c865dcf6e9f20bfe66a360d4b62941ef769b8 or 368449e467d5f1e2c2e987bf2bd57000ba75e10b, 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 6.6.140, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 1d4b241482d9025c537afb3c7c8419c72c0e0c82; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, a1a99837bb6169cfb9187abaa2005e8f12079426; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, b88c865dcf6e9f20bfe66a360d4b62941ef769b8; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 368449e467d5f1e2c2e987bf2bd57000ba75e10b; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 6c5dc6d68e6ba7f0224a757a39ed52fcdb54d472; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 00155f336a5e8b1006d2ca9ae7ad8fc4a44bb401; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 0cc9847c64cb6e61118bc78c9187c8209a7197fa; 23721387c409087fd3b97e274f34d3ddc0970b74 up to, but not including, 4ae1709a314060a196981b344610d023ea841e57; and 1 more ranges | 1d4b241482d9025c537afb3c7c8419c72c0e0c82, a1a99837bb6169cfb9187abaa2005e8f12079426, b88c865dcf6e9f20bfe66a360d4b62941ef769b8, 368449e467d5f1e2c2e987bf2bd57000ba75e10b, 6c5dc6d68e6ba7f0224a757a39ed52fcdb54d472, 00155f336a5e8b1006d2ca9ae7ad8fc4a44bb401 |
| Linux | Linux Kernel | 3.5 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, 6.6.140; 6.7 up to, but not including, 6.12.90; 6.13 up to, but not including, 6.18.32; 6.19 up to, but not including, 7.0.9; 7.1 | 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.90, 6.18.32 |
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: batman-adv: bla: prevent use-after-free when deleting claims When batadv_bla_del_backbone_claims() removes all claims for a backbone, it does this by dropping the link entry in the hash list. This list entry itself was one of the references which need to be dropped at the same time via batadv_claim_put(). But the batadv_claim_put() must not be done before the last access to the claim object in this function. Otherwise the claim might be freed already by the batadv_claim_release() function before the list entry was dropped.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/00155f336a5e8b1006d2ca9ae7ad8fc4a44bb401
- git.kernel.org/stable/c/0cc9847c64cb6e61118bc78c9187c8209a7197fa
- git.kernel.org/stable/c/1d4b241482d9025c537afb3c7c8419c72c0e0c82
- git.kernel.org/stable/c/368449e467d5f1e2c2e987bf2bd57000ba75e10b
- git.kernel.org/stable/c/4ae1709a314060a196981b344610d023ea841e57
- git.kernel.org/stable/c/6c5dc6d68e6ba7f0224a757a39ed52fcdb54d472
- git.kernel.org/stable/c/a1a99837bb6169cfb9187abaa2005e8f12079426
- git.kernel.org/stable/c/b88c865dcf6e9f20bfe66a360d4b62941ef769b8
Recent Use After Free vulnerabilities
- 8.3 High severity
- 8.8 High severity
- 8.3 High severity
- 8.3 High severity
- 8.8 High severity
- 7.5 High severity
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