Linux: NULL Pointer Dereference
CVE-2026-68385 is a critical-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 5fc0a2a6eeb99cac991242bb48796c7749ce3261, 1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722, 898bb2814f38399108bdd2113f38d97383a7036a 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 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 5fc0a2a6eeb99cac991242bb48796c7749ce3261 or 1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722 or 898bb2814f38399108bdd2113f38d97383a7036a or 4bb06b60d982355e22647b3d12d6619419f8c1fa, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | dcd3e1de9d17dc43dfed87a9fc814b9dec508043 up to, but not including, 5fc0a2a6eeb99cac991242bb48796c7749ce3261; dcd3e1de9d17dc43dfed87a9fc814b9dec508043 up to, but not including, 1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722; dcd3e1de9d17dc43dfed87a9fc814b9dec508043 up to, but not including, 898bb2814f38399108bdd2113f38d97383a7036a; dcd3e1de9d17dc43dfed87a9fc814b9dec508043 up to, but not including, 4bb06b60d982355e22647b3d12d6619419f8c1fa; 6.9 | 5fc0a2a6eeb99cac991242bb48796c7749ce3261, 1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722, 898bb2814f38399108bdd2113f38d97383a7036a, 4bb06b60d982355e22647b3d12d6619419f8c1fa |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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:N/AC:L/PR:N/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: s390/checksum: Fix csum_partial() without vector facility Currently csum_partial() calls csum_copy() with copy=false and dst=NULL. On machines without the vector facility, csum_copy() falls back to cksm(dst, ...), causing the checksum to be calculated from address zero instead of the source buffer. The VX implementation already checksums data loaded from src. Make the fallback do the same by passing src to cksm().
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: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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