Skip to main content
VulnerabilityPublished Updated

CVE-2026-64015: Linux kernel · security/keys: fix missed RCU read section on lookup

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in cefa4265b11176c897a7d9e8e54d89e3701c5584 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in cefa4265b11176c897a7d9e8e54d89e3701c5584, 66288dcadf80974436250e9f70ed848836b835b5, 5659e6923cb72f8e18e8b539109ab512455fe195 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < cefa4265b11176c897a7d9e8e54d89e3701c5584
Fixed in
  • cefa4265b11176c897a7d9e8e54d89e3701c5584
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 66288dcadf80974436250e9f70ed848836b835b5
Fixed in
  • 66288dcadf80974436250e9f70ed848836b835b5
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 5659e6923cb72f8e18e8b539109ab512455fe195
Fixed in
  • 5659e6923cb72f8e18e8b539109ab512455fe195
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 50bb3435a5e627bfbdc52eb4536f49f88b3486b8
Fixed in
  • 50bb3435a5e627bfbdc52eb4536f49f88b3486b8
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 43a1e3744548e6fd85873e6fb43e293eb4010694
Fixed in
  • 43a1e3744548e6fd85873e6fb43e293eb4010694
LinuxLinuxAffected
  • ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc
Fixed in
  • 4c5d407ba3ff7f30561ff73ba1b07ed70c864edc

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.

References

Community reviews

Loading reviews…