CVE-2026-23457
netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary. For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser. Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length.
INFO
Published Date :
April 3, 2026, 4:16 p.m.
Last Modified :
May 26, 2026, 2:40 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Verify Content-Length parsing logic.
- Apply patches for related issues.
Public PoC/Exploit Available at Github
CVE-2026-23457 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-2026-23457.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23457 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-2026-23457
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).
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-23457 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23457 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.
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Initial Analysis by [email protected]
May. 26, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.130 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.203 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.167 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.78 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.20 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.34 up to (excluding) 5.10.253 Added Reference Type kernel.org: https://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 18, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f Added Reference https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 03, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary. For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser. Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length. Added Reference https://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383 Added Reference https://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659 Added Reference https://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9 Added Reference https://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027 Added Reference https://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015 Added Reference https://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c