CVE-2026-23204
net/sched: cls_u32: use skb_header_pointer_careful()
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: use skb_header_pointer_careful() skb_header_pointer() does not fully validate negative @offset values. Use skb_header_pointer_careful() instead. GangMin Kim provided a report and a repro fooling u32_classify(): BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221
INFO
Published Date :
Feb. 14, 2026, 5:15 p.m.
Last Modified :
April 3, 2026, 2:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to a patched version.
- Verify the kernel version is not vulnerable.
- Reboot the system after kernel update.
Public PoC/Exploit Available at Github
CVE-2026-23204 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-23204.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23204 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-23204
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-23204 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23204 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 25, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/cfa745830e45ecb75c061aa34330ee0cac941cc7 -
Initial Analysis by [email protected]
Mar. 19, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Added CWE CWE-125 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:2.6.35:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.35:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.35:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.35:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.35:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:2.6.35:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.70 *cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.10 *cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.35.1 up to (excluding) 6.6.124 Added Reference Type kernel.org: https://git.kernel.org/stable/c/13336a6239b9d7c6e61483017bb8bdfe3ceb10a5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/8a672f177ebe19c93d795fbe967846084fbc7943 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cabd1a976375780dabab888784e356f574bbaed8 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e41a23e61259f5526af875c3b86b3d42a9bae0e5 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 14, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: use skb_header_pointer_careful() skb_header_pointer() does not fully validate negative @offset values. Use skb_header_pointer_careful() instead. GangMin Kim provided a report and a repro fooling u32_classify(): BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221 Added Reference https://git.kernel.org/stable/c/13336a6239b9d7c6e61483017bb8bdfe3ceb10a5 Added Reference https://git.kernel.org/stable/c/8a672f177ebe19c93d795fbe967846084fbc7943 Added Reference https://git.kernel.org/stable/c/cabd1a976375780dabab888784e356f574bbaed8 Added Reference https://git.kernel.org/stable/c/e41a23e61259f5526af875c3b86b3d42a9bae0e5