Linux: Improper Locking
CVE-2026-63832 is a high-severity improper locking 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 720f39a9c60fdb604291c630f4f157753b376d68, 3c499851753a24d2e148d4e9ca51764c0c51554e, 55e014aaec650ede08b693ba59c8d0443f13f11c 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 0.23% 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 720f39a9c60fdb604291c630f4f157753b376d68 or 3c499851753a24d2e148d4e9ca51764c0c51554e or 55e014aaec650ede08b693ba59c8d0443f13f11c or 20b126920a259df4d7dcae19fcfe2c57a74d6b2e, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.114 or 6.18.38 or 7.1.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | c9389e3f9453ec2d710e61830eafedddfd561226 up to, but not including, 720f39a9c60fdb604291c630f4f157753b376d68; 4911e4cb157cf87d5bdb3fa8e0c200032443371e up to, but not including, 3c499851753a24d2e148d4e9ca51764c0c51554e; 4911e4cb157cf87d5bdb3fa8e0c200032443371e up to, but not including, 55e014aaec650ede08b693ba59c8d0443f13f11c; 4911e4cb157cf87d5bdb3fa8e0c200032443371e up to, but not including, 20b126920a259df4d7dcae19fcfe2c57a74d6b2e; 57d3f833087942ded1a8765b1b361454d3d39e8f; 6.12.13 up to, but not including, 6.12.114; 6.13.2 up to, but not including, 6.14; 6.14 | 720f39a9c60fdb604291c630f4f157753b376d68, 3c499851753a24d2e148d4e9ca51764c0c51554e, 55e014aaec650ede08b693ba59c8d0443f13f11c, 20b126920a259df4d7dcae19fcfe2c57a74d6b2e, 6.12.114, 6.14 |
| Linux | Linux Kernel | 6.12.13 up to, but not including, 6.12.114; 6.13.2 up to, but not including, 6.18.38; 6.19 up to, but not including, 7.1.3 | 6.12.114, 6.18.38, 7.1.3 |
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: wifi: mt76: add wcid publish check in mt76_sta_add Since mt7925_mac_sta_add publishes wcid, add publish check in mt76_sta_add to avoid reinitializing the wcid->poll_list. Found dev->sta_poll_list corruption when using mt7925 and 7.1-rc4. According to the corruption information, prev->next was changed to itself. wlan0: disconnect from AP 90:fb:5d:94:8b:e3 for new auth to 90:fb:5d:94:8b:e2 wlan0: authenticate with 90:fb:5d:94:8b:e2 (local address=84:9e:56:9c:7e:6b) wlan0: send auth to 90:fb:5d:94:8b:e2 (try 1/3) slab kmalloc-8k start ffff8c80958a6000 pointer offset 4160 size 8192 list_add corruption. prev->next should be next (ffff8c808a7488f8), but was ffff8c80958a7040. (prev=ffff8c80958a7040). mt76_wcid_add_poll+0x95/0xd0 [mt76] mt7925_mac_add_txs.part.0+0xa5/0xe0 [mt7925_common] mt7925_rx_check+0xa7/0xc0 [mt7925_common] mt76_dma_rx_poll+0x50d/0x790 [mt76] mt792x_poll_rx+0x52/0xe0 [mt792x_lib]
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Locking
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
How developers prevent this class of flaw
- Use industry standard APIs to implement locking mechanism.
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
Recent Improper Locking vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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