Linux: Out-of-bounds Read
CVE-2026-64490 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions 3243563f99ef5d3949b934bd6390a5679405d0e1, 5da9742de22db0dbaa8d414214ab5e1bedde00f9, 21584672fd699abe1768241d6c501b2de6139b6a 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 0.19% 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 3243563f99ef5d3949b934bd6390a5679405d0e1 or 5da9742de22db0dbaa8d414214ab5e1bedde00f9 or 21584672fd699abe1768241d6c501b2de6139b6a or c77a6cbb36ff8cbc1f084d94f8dcda5250935271, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.96 or 6.18.39 or 7.1.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d6568e3de42dd971a1356f7ba581e6600d53f0a0 up to, but not including, 3243563f99ef5d3949b934bd6390a5679405d0e1; d6568e3de42dd971a1356f7ba581e6600d53f0a0 up to, but not including, 5da9742de22db0dbaa8d414214ab5e1bedde00f9; d6568e3de42dd971a1356f7ba581e6600d53f0a0 up to, but not including, 21584672fd699abe1768241d6c501b2de6139b6a; d6568e3de42dd971a1356f7ba581e6600d53f0a0 up to, but not including, c77a6cbb36ff8cbc1f084d94f8dcda5250935271; 6.9 | 3243563f99ef5d3949b934bd6390a5679405d0e1, 5da9742de22db0dbaa8d414214ab5e1bedde00f9, 21584672fd699abe1768241d6c501b2de6139b6a, c77a6cbb36ff8cbc1f084d94f8dcda5250935271 |
| Linux | Linux Kernel | 6.9 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4 | 6.12.96, 6.18.39, 7.1.4 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- 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:L/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: ALSA: virtio: Validate control metadata from the device virtio-snd control handling trusts the device-provided control type and value count returned by the device. That metadata is then used directly to index g_v2a_type_map[] in virtsnd_kctl_info(), and to size loops and memcpy() operations in virtsnd_kctl_get() and virtsnd_kctl_put() against fixed-size virtio_snd_ctl_value and snd_ctl_elem_value arrays. A buggy or malicious device can therefore trigger out-of-bounds access by advertising an invalid control type or an oversized value count. Validate control type and count once in virtsnd_kctl_parse_cfg(), before querying enumerated items or exposing the control to ALSA.
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
- 7.1 High severity
- 7.1 High severity
- 7.7 High severity
- 9.1 Critical severity
- 8.2 High severity
- 8.8 High severity
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