Linux: Out-of-bounds Read
CVE-2026-64255 is a high-severity out-of-bounds read 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 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b, fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc, f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 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 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b or fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc or f056fc2b927448d37eca6b6cacc3d1b0f67b20d2, whichever matches your release line, or a later version.
- Update Linux Kernel to 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 | 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b up to, but not including, 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b; 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b up to, but not including, fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc; 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b up to, but not including, f056fc2b927448d37eca6b6cacc3d1b0f67b20d2; 6.4 | 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b, fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc, f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 |
| Linux | Linux Kernel | 6.4 up to, but not including, 6.18.38; 6.19 up to, but not including, 7.1.3 | 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: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers Three BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a station ID without checking that sta_mask is non-zero. When sta_mask is zero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing an out-of-bounds access on fw_id_to_link_sta[]. Add WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call, consistent with the existing check in iwl_mld_ampdu_rx_start().
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: total).
- 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
- 8.4 High severity
- 7.1 High severity
- 8.1 High severity
- 7.1 High severity
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