Linux: Out-of-bounds Read
CVE-2026-64223 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 8.1 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 f7d395dc5008168ac5b9c1ac2791e59a6078cca1, 2dd9304727c7041df0a599595910bdbe02ad03c5, 2becaaeebe230ade1fcd5d0f1cde4d6ee93ec78f 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 0.39% 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 f7d395dc5008168ac5b9c1ac2791e59a6078cca1 or 2dd9304727c7041df0a599595910bdbe02ad03c5 or 2becaaeebe230ade1fcd5d0f1cde4d6ee93ec78f or a6e6ccd5bd07155c2add6c74ce1a5e68ad3b95ea, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.92 or 6.18.34 or 7.0.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8f500fbc6c655976c8062b1f1e55bd0b3095d6c2 up to, but not including, f7d395dc5008168ac5b9c1ac2791e59a6078cca1; 8f500fbc6c655976c8062b1f1e55bd0b3095d6c2 up to, but not including, 2dd9304727c7041df0a599595910bdbe02ad03c5; 8f500fbc6c655976c8062b1f1e55bd0b3095d6c2 up to, but not including, 2becaaeebe230ade1fcd5d0f1cde4d6ee93ec78f; 8f500fbc6c655976c8062b1f1e55bd0b3095d6c2 up to, but not including, a6e6ccd5bd07155c2add6c74ce1a5e68ad3b95ea; 6.9 | f7d395dc5008168ac5b9c1ac2791e59a6078cca1, 2dd9304727c7041df0a599595910bdbe02ad03c5, 2becaaeebe230ade1fcd5d0f1cde4d6ee93ec78f, a6e6ccd5bd07155c2add6c74ce1a5e68ad3b95ea |
| Linux | Linux Kernel | 6.9 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.1 | 6.12.92, 6.18.34, 7.0.11 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements against the number of link-map entries indicated by link_map_presence. ieee80211_parse_neg_ttlm() must consume the same layout. The parser advanced its cursor for every TID, including TIDs whose presence bit is clear and therefore have no map bytes in the element. A sparse map can then make a later present TID read past the validated element. The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by valid_links before being applied to driver state, so a peer cannot turn the read into a policy change. Under KUnit + KASAN with an exact-sized element allocation the OOB read is reported as a slab-out-of-bounds; whether the same trigger fires under the production RX path depends on surrounding allocator state. Advance the cursor only when the current TID has a map present.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
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
Recent Out-of-bounds Read vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 8.4 High severity
- 7.1 High severity
- 7.1 High severity
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