CyberSecBulletin
CVE-2026-64222NVD status: Modified

Linux: Double Free

Published Updated By the CyberSecBulletin desk

CVE-2026-64222 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.0 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 e6e9bc0bf963662b7042048ab0281014625d4cb4, b92e7ea408b6f1144648909c9c49a55d245d7300, 94192b0579333c3deee2441379aab8ca98fc2e6b 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.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to e6e9bc0bf963662b7042048ab0281014625d4cb4 or b92e7ea408b6f1144648909c9c49a55d245d7300 or 94192b0579333c3deee2441379aab8ca98fc2e6b or 4c29603498b05c049dbbbc47e882f2fbf0193cd7, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxcaa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, e6e9bc0bf963662b7042048ab0281014625d4cb4; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, b92e7ea408b6f1144648909c9c49a55d245d7300; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, 94192b0579333c3deee2441379aab8ca98fc2e6b; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, 4c29603498b05c049dbbbc47e882f2fbf0193cd7; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, 0488a0bb344fb1992853b60082acff6be8164d74; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, 0d9b9d7dbef976ae7f855b6358f1d703014e96ea; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, c4b8c5d51632538b19ee01cf6d70cbceeefbd3ec; caa2da34fd25a37e9fd43343b6966fb9d730a6d5 up to, but not including, 9b244c242bec48b37e82b89787afd6a4c43457e1; and 1 more rangese6e9bc0bf963662b7042048ab0281014625d4cb4, b92e7ea408b6f1144648909c9c49a55d245d7300, 94192b0579333c3deee2441379aab8ca98fc2e6b, 4c29603498b05c049dbbbc47e882f2fbf0193cd7, 0488a0bb344fb1992853b60082acff6be8164d74, 0d9b9d7dbef976ae7f855b6358f1d703014e96ea
LinuxLinux Kernel5.6 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.11; 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35

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
HighSuccess depends on conditions outside the attacker's control.
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:H/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: octeontx2-pf: avoid double free of pool->stack on AQ init failure otx2_pool_aq_init() frees pool->stack when mailbox sync or retry allocation fails, but leaves the pointer unchanged. Later, otx2_sq_aura_pool_init() unwinds the partial setup through otx2_aura_pool_free(), which frees pool->stack again. The CN20K-specific cn20k_pool_aq_init() implementation has the same bug in its corresponding error path. Set pool->stack to NULL immediately after the local free so the shared cleanup path does not free the same stack again while cleaning up partially initialized pool state. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1-rc3. Runtime validation was not performed because reproducing this path requires OcteonTX2/CN20K hardware.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Double Free

The product calls free() twice on the same memory address.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
  • Use a static analysis tool to find double free instances.

More Double Free vulnerabilities (CWE-415)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Double Free vulnerabilities

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