SB20260720318 - Insufficient verification of data authenticity in Linux kernel netfilter

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Main Vulnerability Database SB20260720318

SB20260720318 - Insufficient verification of data authenticity in Linux kernel netfilter

Published: July 20, 2026

Security Bulletin ID SB20260720318
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Partial DoS

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Insufficient verification of data authenticity (CVE-ID: CVE-2026-63913)

CWE-ID: CWE-345 - Insufficient Verification of Data Authenticity

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper state validation in the TCP conntrack state machine in netfilter conntrack when processing a crafted SYN followed by an invalid-sequence RST packet. A remote attacker can send a specially crafted packet sequence to cause a denial of service.

The issue can prematurely terminate an active NAT entry by forcing the conntrack entry into the CLOSE state.


Remediation

Install update from vendor's website.

References