Linux: Out-of-bounds Read
CVE-2026-64559 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 0a9e34ccbe772b8f321388cdbdf4f22b94e513e7, 693bf91d4db134f9b1c2840c8e287eee3d993bac, 7e7e03848c918aa0acad5ffd75d929e3afec1554 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 0.12% 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 0a9e34ccbe772b8f321388cdbdf4f22b94e513e7 or 693bf91d4db134f9b1c2840c8e287eee3d993bac or 7e7e03848c918aa0acad5ffd75d929e3afec1554 or b3d4ab2d7df9426f7f1d3671d7e2108f2ca6e970, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.97 or 6.18.40 or 7.1.5, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8fcc231ce3bea12b78bb94b280cdc03cff342435 up to, but not including, 0a9e34ccbe772b8f321388cdbdf4f22b94e513e7; 8fcc231ce3bea12b78bb94b280cdc03cff342435 up to, but not including, 693bf91d4db134f9b1c2840c8e287eee3d993bac; 8fcc231ce3bea12b78bb94b280cdc03cff342435 up to, but not including, 7e7e03848c918aa0acad5ffd75d929e3afec1554; 8fcc231ce3bea12b78bb94b280cdc03cff342435 up to, but not including, b3d4ab2d7df9426f7f1d3671d7e2108f2ca6e970; 6.12 | 0a9e34ccbe772b8f321388cdbdf4f22b94e513e7, 693bf91d4db134f9b1c2840c8e287eee3d993bac, 7e7e03848c918aa0acad5ffd75d929e3afec1554, b3d4ab2d7df9426f7f1d3671d7e2108f2ca6e970 |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.12.97; 6.13 up to, but not including, 6.18.40; 6.19 up to, but not including, 7.1.5 | 6.12.97, 6.18.40, 7.1.5 |
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
- LowA basic user account is enough.
- 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:L/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: s390/pkey: Check length in PKEY_VERIFYPROTK ioctl Explicitly check the buffer length request structure provided by user-space and fail, if it exceeds the buffer size.
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
- 8.1 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.1 High severity
- 9.1 Critical severity
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