Linux: Use After Free
CVE-2026-98117 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 68d459e6e609c31f96a203dd6eec60c634f155e1, 93488ea378b4427598cace558236c110515d743b, a67632c8c2688d6e0091529bcefe54bc5ee80e9b 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 68d459e6e609c31f96a203dd6eec60c634f155e1 or 93488ea378b4427598cace558236c110515d743b or a67632c8c2688d6e0091529bcefe54bc5ee80e9b, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.53 or 7.2.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 229105e5cfd9832a9ef1368c96e0098ec3a5fbf0 up to, but not including, 68d459e6e609c31f96a203dd6eec60c634f155e1; 229105e5cfd9832a9ef1368c96e0098ec3a5fbf0 up to, but not including, 93488ea378b4427598cace558236c110515d743b; 229105e5cfd9832a9ef1368c96e0098ec3a5fbf0 up to, but not including, a67632c8c2688d6e0091529bcefe54bc5ee80e9b; 6.14 | 68d459e6e609c31f96a203dd6eec60c634f155e1, 93488ea378b4427598cace558236c110515d743b, a67632c8c2688d6e0091529bcefe54bc5ee80e9b |
| Linux | Linux Kernel | 6.14 up to, but not including, 6.18.53; 6.19 up to, but not including, 7.2.7; 7.3 | 6.18.53, 7.2.7 |
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: cachefiles: Fix potential UAF/KASAN warning Currently, trace_cachefiles_coherency() is being passed a pointer to a __be64 lain over the coherency data in struct cachefiles_xattr so that it can display the first 8 bytes. However, the data is of variable length and could even be 0 bytes. This could lead to a UAF or KASAN warning. Fix this by making sure the buffer has room for at least 8 bytes and that those 8 bytes are pre-cleared. Further, those bytes are not 8-byte aligned, so fix the tracepoint to extract the data as four 2-byte words (they are 2-byte aligned) and reassemble the __be64. The compiler will convert this into a single 8-byte load where the CPU supports it.
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
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 9.8 Critical severity
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