Linux: NULL Pointer Dereference
CVE-2026-43101 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 dd0d2827b3643ff307c766865f8e31eab5cbd1f5, 34b8390ac0ba57004b90ea568ac06f50bf896a80, f87aa5d1a7f56727a768757613a303b4245444a1 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 0.58% 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 dd0d2827b3643ff307c766865f8e31eab5cbd1f5 or 34b8390ac0ba57004b90ea568ac06f50bf896a80 or f87aa5d1a7f56727a768757613a303b4245444a1 or 4198aab6f000b4febb18ea820fea20634dd789c7, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.24 or 6.19.14, 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 | 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, dd0d2827b3643ff307c766865f8e31eab5cbd1f5; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, 34b8390ac0ba57004b90ea568ac06f50bf896a80; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, f87aa5d1a7f56727a768757613a303b4245444a1; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, 4198aab6f000b4febb18ea820fea20634dd789c7; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, 3719c234fa94c37c955b1ecd3742ef280ec135e6; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 up to, but not including, 4e65a8b8daa18d63255ec58964dd192c7fdd9f8b; 5.15 | dd0d2827b3643ff307c766865f8e31eab5cbd1f5, 34b8390ac0ba57004b90ea568ac06f50bf896a80, f87aa5d1a7f56727a768757613a303b4245444a1, 4198aab6f000b4febb18ea820fea20634dd789c7, 3719c234fa94c37c955b1ecd3742ef280ec135e6, 4e65a8b8daa18d63255ec58964dd192c7fdd9f8b |
| Linux | Linux Kernel | 5.15 up to, but not including, 6.18.24; 6.19 up to, but not including, 6.19.14; 7.0 | 6.18.24, 6.19.14 |
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: ipv6: ioam: fix potential NULL dereferences in __ioam6_fill_trace_data() We need to check __in6_dev_get() for possible NULL value, as suggested by Yiming Qian. Also add skb_dst_dev_rcu() instead of skb_dst_dev(), and two missing READ_ONCE(). Note that @dev can't be NULL.
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
Other references
Recent NULL Pointer Dereference vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 9.1 Critical severity
- 8.8 High severity
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