---
id: CVE-2026-61548
title: Rsyslog is a rocket-fast system for log processing
summary: >-
  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] st…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-121
vendor: rsyslog
product: rsyslog
affected:
  - 'rsyslog >= 7.5.4, < 8.2606.0'
published: '2026-09-18'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T21:17:06.633'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61548'
references:
  - url: >-
      https://github.com/rsyslog/rsyslog/commit/bcda60a3692efdf0c8e44102528f5a0ebe0dec6d
    label: security-advisories@github.com
  - url: 'https://github.com/rsyslog/rsyslog/pull/6991'
    label: security-advisories@github.com
  - url: 'https://github.com/rsyslog/rsyslog/releases/tag/v8.2606.0'
    label: security-advisories@github.com
  - url: 'https://github.com/rsyslog/rsyslog/security/advisories/GHSA-8qmr-c66f-g368'
    label: security-advisories@github.com
  - url: 'http://www.openwall.com/lists/oss-security/2026/07/20/1'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T19:24:39.206415Z'
epss: 0.00592
epssPercentile: 0.47033
ingestedAt: '2026-09-18T17:46:41.520Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.