Linux: Double Free
CVE-2026-63822 is a high-severity double free 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 e569a5cb401a267168621aa9a1e7f07fcc9612c3, 0aa097a370277deab5337030b9e2d395742f469c, 0a946abb82f29abe9a15173b707a449cb039b43e 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 0.13% 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 e569a5cb401a267168621aa9a1e7f07fcc9612c3 or 0aa097a370277deab5337030b9e2d395742f469c or 0a946abb82f29abe9a15173b707a449cb039b43e or 318703b6f71d1a29ee0ac46c32a38f7734d4cfb2, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.260 or 5.15.211 or 6.1.177 or 6.6.144, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, e569a5cb401a267168621aa9a1e7f07fcc9612c3; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 0aa097a370277deab5337030b9e2d395742f469c; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 0a946abb82f29abe9a15173b707a449cb039b43e; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 318703b6f71d1a29ee0ac46c32a38f7734d4cfb2; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 7b2e62b9080bf4a5f4e70cfe47156df8d93a4f13; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 40aa3c2b0cb8e34e0576fc94cc70e4e33db03c0a; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 051f954b94479d72222c9fbc82a3eef4777bca01; d5c65159f2895379e11ca13f62feabe93278985d up to, but not including, 8b7a26b6681922a38cd5a7829ace61f8e54df9b7; and 1 more ranges | e569a5cb401a267168621aa9a1e7f07fcc9612c3, 0aa097a370277deab5337030b9e2d395742f469c, 0a946abb82f29abe9a15173b707a449cb039b43e, 318703b6f71d1a29ee0ac46c32a38f7734d4cfb2, 7b2e62b9080bf4a5f4e70cfe47156df8d93a4f13, 40aa3c2b0cb8e34e0576fc94cc70e4e33db03c0a |
| Linux | Linux Kernel | 5.6 up to, but not including, 5.10.260; 5.11 up to, but not including, 5.15.211; 5.16 up to, but not including, 6.1.177; 6.2 up to, but not including, 6.6.144; 6.7 up to, but not including, 6.12.95; 6.13 up to, but not including, 6.18.38; 6.19 up to, but not including, 7.1.3 | 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38 |
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 NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: ath11k: fix warning when unbinding If there is an error during some initialization related to firmware, the buffers dp->tx_ring[i].tx_status are released. However this is released again when the device is unbinded (ath11k_pci), and we get: WARNING: CPU: 0 PID: 6231 at mm/slub.c:4368 free_large_kmalloc+0x57/0x90 Call Trace: free_large_kmalloc ath11k_dp_free ath11k_core_deinit ath11k_pci_remove ... The issue is always reproducible from a VM because the MSI addressing initialization is failing. In order to fix the issue, just set the buffers to NULL after releasing in order to avoid the double free.
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.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/051f954b94479d72222c9fbc82a3eef4777bca01
- git.kernel.org/stable/c/0a946abb82f29abe9a15173b707a449cb039b43e
- git.kernel.org/stable/c/0aa097a370277deab5337030b9e2d395742f469c
- git.kernel.org/stable/c/318703b6f71d1a29ee0ac46c32a38f7734d4cfb2
- git.kernel.org/stable/c/40aa3c2b0cb8e34e0576fc94cc70e4e33db03c0a
- git.kernel.org/stable/c/7b2e62b9080bf4a5f4e70cfe47156df8d93a4f13
- git.kernel.org/stable/c/8b7a26b6681922a38cd5a7829ace61f8e54df9b7
- git.kernel.org/stable/c/e569a5cb401a267168621aa9a1e7f07fcc9612c3
Recent Double Free vulnerabilities
- 8.4 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.7 High severity
- 9.8 Critical severity
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