Linux: Double Free
CVE-2026-68236 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 92b7c6e3a1546c6db868b07e93fa6fb950d1d3a0, bf9c06c70f496f1ba4474caf95c69696c828340e, 01ba5b36898d6258f584269537cc49e7b05cf7c6 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 92b7c6e3a1546c6db868b07e93fa6fb950d1d3a0 or bf9c06c70f496f1ba4474caf95c69696c828340e or 01ba5b36898d6258f584269537cc49e7b05cf7c6 or ba8bf1dcbb44773e7a0fd13b42925c644e0d5e76, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 92b7c6e3a1546c6db868b07e93fa6fb950d1d3a0; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, bf9c06c70f496f1ba4474caf95c69696c828340e; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 01ba5b36898d6258f584269537cc49e7b05cf7c6; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, ba8bf1dcbb44773e7a0fd13b42925c644e0d5e76; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 5182e442e61397d446c36995b8f5676942d35b82; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 679f23f0a3606afcef1ffabd72222f00a54ad9e3; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 0676fecbb5242aa22c057e78326d6d6041db034c; 9b690ef3c70422cdcd0cf912db33f2c92ef4a53f up to, but not including, 9fa26b9eed6195bf840f39ac183b9a6237548755; and 1 more ranges | 92b7c6e3a1546c6db868b07e93fa6fb950d1d3a0, bf9c06c70f496f1ba4474caf95c69696c828340e, 01ba5b36898d6258f584269537cc49e7b05cf7c6, ba8bf1dcbb44773e7a0fd13b42925c644e0d5e76, 5182e442e61397d446c36995b8f5676942d35b82, 679f23f0a3606afcef1ffabd72222f00a54ad9e3 |
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: drm/amd/display: set new_stream to NULL after release In dm_update_crtc_state(), the skip_modeset path releases new_stream via dc_stream_release() but does not set the pointer to NULL. If a later error (e.g., color management failure) triggers the fail label, the error path calls dc_stream_release() again on the same dangling pointer, causing a double release and potential use-after-free. Fix this by setting new_stream to NULL after the initial release. (cherry picked from commit 99f3af19073b3ddbfd96e789124cce12c4277b28)
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
- git.kernel.org/stable/c/01ba5b36898d6258f584269537cc49e7b05cf7c6
- git.kernel.org/stable/c/0676fecbb5242aa22c057e78326d6d6041db034c
- git.kernel.org/stable/c/5182e442e61397d446c36995b8f5676942d35b82
- git.kernel.org/stable/c/679f23f0a3606afcef1ffabd72222f00a54ad9e3
- git.kernel.org/stable/c/92b7c6e3a1546c6db868b07e93fa6fb950d1d3a0
- git.kernel.org/stable/c/9fa26b9eed6195bf840f39ac183b9a6237548755
- git.kernel.org/stable/c/ba8bf1dcbb44773e7a0fd13b42925c644e0d5e76
- git.kernel.org/stable/c/bf9c06c70f496f1ba4474caf95c69696c828340e
Recent Double Free vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
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