CVE-2026-23455
Received Received - Intake
Out-of-Bounds Read in Linux Kernel netfilter nf_conntrack_h

Publication date: 2026-04-03

Last updated on: 2026-04-27

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-04-03
Last Modified
2026-04-27
Generated
2026-05-07
AI Q&A
2026-04-03
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux_kernel linux_kernel *
linux linux_kernel *
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's netfilter component, specifically in the nf_conntrack_h323 module within the DecodeQ931() function.

The issue arises because the function reads a 16-bit length value from a packet and then decrements it by 1 to skip a protocol discriminator byte. If the original length is zero, decrementing it causes an integer wrap to -1, which is interpreted as a very large positive value when passed to the decoder.

This leads to an out-of-bounds read in the decoder, which can cause unexpected behavior or crashes.

The fix involves adding a check to ensure the length remains positive after decrementing, preventing the wrap and subsequent out-of-bounds read.


How can this vulnerability impact me? :

This vulnerability can lead to an out-of-bounds read in the Linux kernel's netfilter nf_conntrack_h323 module.

Such out-of-bounds reads may cause system instability, crashes, or potentially allow attackers to read sensitive memory areas, depending on the context and exploitation.

Therefore, it could impact system reliability and security, possibly leading to denial of service or information disclosure.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart