CVE-2026-23204
Buffer Overflow in Linux Kernel cls_u32 Causes KASAN Crash
Publication date: 2026-02-14
Last updated on: 2026-04-03
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 2.6.35 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 6.7 (inc) to 6.12.70 (exc) |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 6.13 (inc) to 6.18.10 (exc) |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | 6.19 |
| linux | linux_kernel | From 2.6.35.1 (inc) to 6.6.124 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-125 | The product reads data past the end, or before the beginning, of the intended buffer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's network scheduler component, specifically in the cls_u32 classifier. The issue arises because the function skb_header_pointer() does not properly validate negative offset values, which can lead to out-of-bounds memory access.
The fix involved replacing skb_header_pointer() with skb_header_pointer_careful(), which performs more thorough validation of the offset values to prevent such errors.
The vulnerability was reported by GangMin Kim, who also provided a reproduction method that fools the u32_classify() function, causing a kernel slab-out-of-bounds bug detected by KASAN (Kernel Address Sanitizer).
How can this vulnerability impact me? :
This vulnerability can lead to out-of-bounds memory access within the Linux kernel's network scheduler, which may cause system instability, crashes, or potentially allow an attacker to execute arbitrary code or escalate privileges.
Since the issue involves kernel memory corruption, it could be exploited to compromise the security and reliability of affected systems.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
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What immediate steps should I take to mitigate this vulnerability?
I don't know