Input validation error in rsyslog - CVE-2026-19654

Vulnerability identifier: #VU139164

CSH Severity: Medium

CVSS v4: 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]

CVE-ID: CVE-2026-19654

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

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.

rsyslog
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
openEuler
Anolis OS
rsyslog-crypto
rsyslog
rsyslog-help
rsyslog-udpspoof
rsyslog-snmp
rsyslog-relp
rsyslog-rabbitmq
rsyslog-pgsql
rsyslog-omamqp1
rsyslog-mysql
rsyslog-mongodb
rsyslog-mmsnmptrapd
rsyslog-mmkubernetes
rsyslog-mmnormalize
rsyslog-debuginfo
rsyslog-debugsource
rsyslog-elasticsearch
rsyslog-gnutls
rsyslog-gssapi
rsyslog-hiredis
rsyslog-kafka
rsyslog-mmaudit
rsyslog-mmjsonparse
rsyslog-openssl
rsyslog-doc
rsyslog-mmfields
rsyslog-logrotate
rsyslog-libdbi
rsyslog (Red Hat package)

Install security update from vendor's website.

rsyslog - update to 8.2608.0
rsyslog-crypto - update to 8.2210.0-11
rsyslog - update to 8.2210.0-11
rsyslog-help - update to 8.2210.0-11
rsyslog-udpspoof - update to 8.2210.0-11
rsyslog-snmp - update to 8.2210.0-11
rsyslog-relp - update to 8.2210.0-11
rsyslog-rabbitmq - update to 8.2210.0-11
rsyslog-pgsql - update to 8.2210.0-11
rsyslog-omamqp1 - update to 8.2210.0-11
rsyslog-mysql - update to 8.2210.0-11
rsyslog-mongodb - update to 8.2210.0-11
rsyslog-mmsnmptrapd - update to 8.2210.0-11
rsyslog-mmkubernetes - update to 8.2210.0-11
rsyslog-mmnormalize - update to 8.2210.0-11
rsyslog-debuginfo - update to 8.2210.0-11
rsyslog-debugsource - update to 8.2210.0-11
rsyslog-elasticsearch - update to 8.2210.0-11
rsyslog-gnutls - update to 8.2210.0-11
rsyslog-gssapi - update to 8.2210.0-11
rsyslog-hiredis - update to 8.2210.0-11
rsyslog-kafka - update to 8.2210.0-11
rsyslog-mmaudit - update to 8.2210.0-11
rsyslog-mmjsonparse - update to 8.2210.0-11
rsyslog-mmkubernetes - update to 8.2312.0-4
rsyslog-mmnormalize - update to 8.2312.0-4
rsyslog-mmsnmptrapd - update to 8.2312.0-4
rsyslog-mysql - update to 8.2312.0-4
rsyslog-omamqp1 - update to 8.2312.0-4
rsyslog-openssl - update to 8.2312.0-4
rsyslog-pgsql - update to 8.2312.0-4
rsyslog-rabbitmq - update to 8.2312.0-4
rsyslog-relp - update to 8.2312.0-4
rsyslog-snmp - update to 8.2312.0-4
rsyslog-udpspoof - update to 8.2312.0-4
rsyslog-doc - update to 8.2312.0-4
rsyslog-mmjsonparse - update to 8.2312.0-4
rsyslog-mmfields - update to 8.2312.0-4
rsyslog-mmaudit - update to 8.2312.0-4
rsyslog-logrotate - update to 8.2312.0-4
rsyslog-libdbi - update to 8.2312.0-4
rsyslog-kafka - update to 8.2312.0-4
rsyslog-hiredis - update to 8.2312.0-4
rsyslog-gssapi - update to 8.2312.0-4
rsyslog-gnutls - update to 8.2312.0-4
rsyslog-elasticsearch - update to 8.2312.0-4
rsyslog-crypto - update to 8.2312.0-4
rsyslog - update to 8.2312.0-4
rsyslog (Red Hat package) - update to 8.2412.0-1.el10_0.1

• https://github.com/rsyslog/rsyslog/security/advisories/GHSA-cj5r-wh2m-7w29

• Input validation error in rsyslog
• openEuler update for rsyslog
• Red Hat Enterprise Linux 10 update for rsyslog
• Anolis OS update for rsyslog