Linux: Use After Free
CVE-2026-23322 is a high-severity use after 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 c08ec55617cb9674a060a3392ea08391ab2a4f74, 65ff5d1e4410df05edfbeb7bf2d62f7681ce1d53, 594c11d0e1d445f580898a2b8c850f2e3f099368 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 c08ec55617cb9674a060a3392ea08391ab2a4f74 or 65ff5d1e4410df05edfbeb7bf2d62f7681ce1d53 or 594c11d0e1d445f580898a2b8c850f2e3f099368, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.17 or 6.19.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9cf93a8fa9513c6d3cc65bdd50e05c1355cef322 up to, but not including, c08ec55617cb9674a060a3392ea08391ab2a4f74; 9cf93a8fa9513c6d3cc65bdd50e05c1355cef322 up to, but not including, 65ff5d1e4410df05edfbeb7bf2d62f7681ce1d53; 9cf93a8fa9513c6d3cc65bdd50e05c1355cef322 up to, but not including, 594c11d0e1d445f580898a2b8c850f2e3f099368; 6.18 | c08ec55617cb9674a060a3392ea08391ab2a4f74, 65ff5d1e4410df05edfbeb7bf2d62f7681ce1d53, 594c11d0e1d445f580898a2b8c850f2e3f099368 |
| Linux | Linux Kernel | 6.18.1 up to, but not including, 6.18.17; 6.19 up to, but not including, 6.19.7; 6.18; 7.0 | 6.18.17, 6.19.7 |
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: ipmi: Fix use-after-free and list corruption on sender error The analysis from Breno: When the SMI sender returns an error, smi_work() delivers an error response but then jumps back to restart without cleaning up properly: 1. intf->curr_msg is not cleared, so no new message is pulled 2. newmsg still points to the message, causing sender() to be called again with the same message 3. If sender() fails again, deliver_err_response() is called with the same recv_msg that was already queued for delivery This causes list_add corruption ("list_add double add") because the recv_msg is added to the user_msgs list twice. Subsequently, the corrupted list leads to use-after-free when the memory is freed and reused, and eventually a NULL pointer dereference when accessing recv_msg->done. The buggy sequence: sender() fails -> deliver_err_response(recv_msg) // recv_msg queued for delivery -> goto restart // curr_msg not cleared! sender() fails again (same message!) -> deliver_err_response(recv_msg) // tries to queue same recv_msg -> LIST CORRUPTION Fix this by freeing the message and setting it to NULL on a send error. Also, always free the newmsg on a send error, otherwise it will leak.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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