SB2026102169 - Red Hat Enterprise Linux 9 update for rsyslog
Published: October 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Input validation error (CVE-ID: CVE-2026-19654)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in the imptcp input module regex framing implementation when processing crafted input over a TCP connection to an imptcp listener configured with framing.delimiter.regex. A remote attacker can send crafted input to cause a denial of service.
The issue affects only deployments that explicitly load the optional imptcp module and configure an imptcp listener with the non-default framing.delimiter.regex setting. Default imptcp framing modes and the imtcp module are not affected.
2) Heap-based buffer overflow (CVE-ID: CVE-2026-78002)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to heap-based buffer overflow in the RainerScript replace() and three-argument wrap() implementation when processing attacker-controlled message content from network input with an affected ruleset. A remote attacker can send a specially crafted message to cause a denial of service.
Exposure requires a configuration that applies replace() or three-argument wrap() to untrusted message data received from a network input.
Remediation
Install update from vendor's website.