Linux: Out-of-bounds Read
CVE-2026-64015 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 1d8d987a2aacde238ecd0f4946f28cef74c42b79, 5036a9aa7f21fbce89a2a8451bbc177bae2e920d, 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc 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 0.15% 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 1d8d987a2aacde238ecd0f4946f28cef74c42b79 or 5036a9aa7f21fbce89a2a8451bbc177bae2e920d or 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc or cefa4265b11176c897a7d9e8e54d89e3701c5584, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.175 or 6.6.142 or 6.12.92 or 6.18.34, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 1d8d987a2aacde238ecd0f4946f28cef74c42b79; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 5036a9aa7f21fbce89a2a8451bbc177bae2e920d; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, cefa4265b11176c897a7d9e8e54d89e3701c5584; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 5659e6923cb72f8e18e8b539109ab512455fe195; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 50bb3435a5e627bfbdc52eb4536f49f88b3486b8; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 66288dcadf80974436250e9f70ed848836b835b5; b2a4df200d570b2c33a57e1ebfa5896e4bc81b69 up to, but not including, 43a1e3744548e6fd85873e6fb43e293eb4010694; and 1 more ranges | 1d8d987a2aacde238ecd0f4946f28cef74c42b79, 5036a9aa7f21fbce89a2a8451bbc177bae2e920d, 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc, cefa4265b11176c897a7d9e8e54d89e3701c5584, 5659e6923cb72f8e18e8b539109ab512455fe195, 50bb3435a5e627bfbdc52eb4536f49f88b3486b8 |
| Linux | Linux Kernel | 3.13 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.142; 6.7 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 | 6.1.175, 6.6.142, 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
- 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: security/keys: fix missed RCU read section on lookup Nicholas Carlini reports that the keyring code calls assoc_array_find() in find_key_to_update() without holding the RCU read lock, while the assoc_array_gc() code really is designed around removing the node from the tree and then freeing it after an RCU grace-period. The regular key handling doesn't see this because holding the keyring semaphore hides any lifetime issues, but the persistent key handling uses a different model. Instead of extending the keyring locking, just do the simple RCU locking that the assoc_array was designed for.
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
- git.kernel.org/stable/c/43a1e3744548e6fd85873e6fb43e293eb4010694
- git.kernel.org/stable/c/4c5d407ba3ff7f30561ff73ba1b07ed70c864edc
- git.kernel.org/stable/c/50bb3435a5e627bfbdc52eb4536f49f88b3486b8
- git.kernel.org/stable/c/5659e6923cb72f8e18e8b539109ab512455fe195
- git.kernel.org/stable/c/66288dcadf80974436250e9f70ed848836b835b5
- git.kernel.org/stable/c/cefa4265b11176c897a7d9e8e54d89e3701c5584
Other references
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.8 High severity
- 7.3 High severity
- 7.1 High severity
- 7.8 High severity
- 9.8 Critical severity
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