Linux: NULL Pointer Dereference
CVE-2026-53281 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 8.8 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 d1a677f9c5e02c4ae49614044ac21296660d1391, 9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153, cdfe3c9f2c9e28a8651ee463c88ad191ced2f840 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 0.14% 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 d1a677f9c5e02c4ae49614044ac21296660d1391 or 9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153 or cdfe3c9f2c9e28a8651ee463c88ad191ced2f840 or 79ea2feb917b05366b49d85573c9c5331f043b2c, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.13 or 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 | 68ec78beb4a3fb0877cbaaf49758c85410c05977 up to, but not including, d1a677f9c5e02c4ae49614044ac21296660d1391; 60f030f7418d3f1d94f2fb207fe3080e1844630b up to, but not including, 9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153; 60f030f7418d3f1d94f2fb207fe3080e1844630b up to, but not including, cdfe3c9f2c9e28a8651ee463c88ad191ced2f840; 60f030f7418d3f1d94f2fb207fe3080e1844630b up to, but not including, 79ea2feb917b05366b49d85573c9c5331f043b2c; df96876be3b064aefc493f760e0639765d13ed0d; 6.12.57 up to, but not including, 6.12.114; 6.13.3 up to, but not including, 6.14; 6.14 | d1a677f9c5e02c4ae49614044ac21296660d1391, 9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153, cdfe3c9f2c9e28a8651ee463c88ad191ced2f840, 79ea2feb917b05366b49d85573c9c5331f043b2c, 6.12.114, 6.14 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Linux | Linux Kernel | 6.12.57 up to, but not including, 6.13; 6.13.3 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10; 7.1 | 6.13, 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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:C/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA |
| CVSS 3.1 | 5.5 | Medium | CNA |
Official description
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption Commit 60f030f7418d ("iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE") fixed a NULL pointer dereference in an unlikely situation partly. If dev_pasid is not found in the dev_pasids list, it remains NULL. However, the teardown operations are executed unconditionally, this lead to a NULL pointer dereference or refcount corruption. If the domain was never attached to this IOMMU, info will be NULL, which would cause an immediate dereference when checking --info->refcnt. Even if info is not NULL, decrementing the refcount without having removed a valid PASID might unbalance the count. This could lead to premature dropping of the refcount to 0, potentially causing a use-after-free for the remaining active devices sharing the domain. Fix it by returning early if dev_pasid is NULL, before executing the teardown operations. Issue found by AI review and suggested by Kevin Tian. https://sashiko.dev/#/patchset/20260421031347.1408890-1-zhenzhong.duan%40intel.com
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
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
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-53281Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2493728Issue Tracking, Third Party Advisory
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53281.jsonThird Party Advisory
Other references
Recent NULL Pointer Dereference vulnerabilities
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- 7.5 High severity
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