Linux: NULL Pointer Dereference
CVE-2026-63972 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 7.5 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 c4152b4e28b3e550ec99351bf900e2c24c2608cc, 7ae590797f9b5c240aaea5773f5f00977a42a846, 5b05aa36ee24297d7296ca58dfd8c448d0e4cda3 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 0.59% 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 c4152b4e28b3e550ec99351bf900e2c24c2608cc or 7ae590797f9b5c240aaea5773f5f00977a42a846 or 5b05aa36ee24297d7296ca58dfd8c448d0e4cda3 or 6.18.35, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.35 or 7.0.12, 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 | fb9f98e1041a30dd5766620a2a64cb472b54caa9 up to, but not including, c4152b4e28b3e550ec99351bf900e2c24c2608cc; 3b194343c25084a8d2fa0c0f2c9e80f3080fd732 up to, but not including, 7ae590797f9b5c240aaea5773f5f00977a42a846; 3b194343c25084a8d2fa0c0f2c9e80f3080fd732 up to, but not including, 5b05aa36ee24297d7296ca58dfd8c448d0e4cda3; 6.18.33 up to, but not including, 6.18.35; 7.0 | c4152b4e28b3e550ec99351bf900e2c24c2608cc, 7ae590797f9b5c240aaea5773f5f00977a42a846, 5b05aa36ee24297d7296ca58dfd8c448d0e4cda3, 6.18.35 |
| Linux | Linux Kernel | 6.18.33 up to, but not including, 6.18.35; 7.0 up to, but not including, 7.0.12; 7.1 | 6.18.35, 7.0.12 |
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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: net: mana: Skip redundant detach on already-detached port When mana_per_port_queue_reset_work_handler() runs after a previous detach succeeded but attach failed, the port is left in a detached state with apc->tx_qp and apc->rxqs already freed. Calling mana_detach() again unconditionally leads to NULL pointer dereferences during queue teardown. Add an early exit in mana_detach() when the port is already in detached state (!netif_device_present) for non-close callers, making it safe to call idempotently. This allows the queue reset handler and other recovery paths to simply retry mana_attach() without redundant teardown.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 8.4 High severity
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