Linux: Improper Check for Unusual or Exceptional Conditions
CVE-2026-63841 is a high-severity improper check for unusual or exceptional conditions 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 d0f6ae14c0452be4fc3aa5cf81c74e68b3243050, 869ce148c0d953570f8307c3e206b47bd5d3be99, 2f8e3da71a1b469b6e157aa3972f1448b3157840 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 0.17% 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 d0f6ae14c0452be4fc3aa5cf81c74e68b3243050 or 869ce148c0d953570f8307c3e206b47bd5d3be99 or 2f8e3da71a1b469b6e157aa3972f1448b3157840, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.33 or 7.0.10, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b8f57b69942b2faa7deee0566cc9306316fe0a74 up to, but not including, d0f6ae14c0452be4fc3aa5cf81c74e68b3243050; b8f57b69942b2faa7deee0566cc9306316fe0a74 up to, but not including, 869ce148c0d953570f8307c3e206b47bd5d3be99; b8f57b69942b2faa7deee0566cc9306316fe0a74 up to, but not including, 2f8e3da71a1b469b6e157aa3972f1448b3157840; 6.14 | d0f6ae14c0452be4fc3aa5cf81c74e68b3243050, 869ce148c0d953570f8307c3e206b47bd5d3be99, 2f8e3da71a1b469b6e157aa3972f1448b3157840 |
| Linux | Linux Kernel | 6.14 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10; 7.1 | 6.18.33, 7.0.10 |
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/amdgpu/jpeg: set no_user_fence for JPEG v5.0.1 ring JPEG rings do not support 64-bit user fence writes, reject CS submissions with user fences. (cherry picked from commit 742a98e2e81702df8fe1b1eccee5223220a03dc2)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Check for Unusual or Exceptional Conditions
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
- Check the results of all functions that return a value and verify that the value is expected.
- If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
More Improper Check for Unusual or Exceptional Conditions vulnerabilities (CWE-754)
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
Patches and release notes
Recent Improper Check for Unusual or Exceptional Conditions vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
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