Stack-based Buffer Overflow Affecting rsyslog package, versions <8.2112.0-2ubuntu2.4


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.94% (60th percentile)

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  • Snyk IDSNYK-UBUNTU2204-RSYSLOG-18025178
  • published24 Jul 2026
  • disclosed18 Sept 2026

Introduced: 24 Jul 2026

CVE-2026-61548  (opens in a new tab)
CWE-121  (opens in a new tab)

How to fix?

Upgrade Ubuntu:22.04 rsyslog to version 8.2112.0-2ubuntu2.4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rsyslog package and not the rsyslog package as distributed by Ubuntu. See How to fix? for Ubuntu:22.04 relevant fixed versions and status.

Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite. Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0.

CVSS Base Scores

version 3.1