---
id: CVE-2026-55841
title: Graylog is a free and open log management platform
summary: >-
  Graylog is a free and open log management platform. Prior to Graylog Server
  versions 6.3.12, 7.0.7, and 7.1.2 and Graylog Forwarder version 7.3, the
  FortiGate key-value syslog parser in
  graylog2-server/src/main/java/org/graylog2/inputs/c…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-138
vendor: graylog2
product: 'org.graylog2:graylog2-server'
affected:
  - 'org.graylog2:graylog2-server < 6.3.12'
  - 'org.graylog2:graylog2-server >= 7.0.0, < 7.0.7'
  - 'org.graylog2:graylog2-server >= 7.1.0, < 7.1.2'
patched:
  - 'org.graylog2:graylog2-server 6.3.12'
  - 'org.graylog2:graylog2-server 7.0.7'
  - 'org.graylog2:graylog2-server 7.1.2'
published: '2026-08-28'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:09:13.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55841'
references:
  - url: >-
      https://github.com/Graylog2/graylog2-server/commit/793df6e8202ea55c15a762e47a2a8a775961dd3f
    label: security-advisories@github.com
  - url: >-
      https://github.com/Graylog2/graylog2-server/commit/85dc699d6319aea433583dc239077a3a799c8627
    label: security-advisories@github.com
  - url: >-
      https://github.com/Graylog2/graylog2-server/commit/d5051e604c962ef3d4e5e8e434d0ff4907d2140d
    label: security-advisories@github.com
  - url: >-
      https://github.com/Graylog2/graylog2-server/commit/dde76d7432c469887d9a95c208083c5f0f73c70d
    label: security-advisories@github.com
  - url: 'https://github.com/Graylog2/graylog2-server/pull/26050'
    label: security-advisories@github.com
  - url: 'https://github.com/Graylog2/graylog2-server/pull/26056'
    label: security-advisories@github.com
  - url: 'https://github.com/Graylog2/graylog2-server/pull/26057'
    label: security-advisories@github.com
  - url: 'https://github.com/Graylog2/graylog2-server/pull/26059'
    label: security-advisories@github.com
  - url: >-
      https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-gqr6-r77p-c2pj
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-gqr6-r77p-c2pj'
tags:
  - nvd
  - ghsa
  - maven
epss: 0.00355
epssPercentile: 0.29316
aliases:
  - GHSA-gqr6-r77p-c2pj
ecosystem: maven
ingestedAt: '2026-08-28T22:26:19.079Z'
---

## Overview

Graylog is a free and open log management platform. Prior to Graylog Server versions 6.3.12, 7.0.7, and 7.1.2 and Graylog Forwarder version 7.3, the FortiGate key-value syslog parser in graylog2-server/src/main/java/org/graylog2/inputs/codecs/GLFortiGateSyslogEvent.java and graylog2-server/src/main/java/org/graylog2/inputs/codecs/SyslogCodec.java mishandles field-like text inside quoted values. GLFortiGateSyslogEvent.getFields() uses KV_PATTERN and QUOTED_KV_PATTERN, while SyslogCodec.parse() invokes the FortiGateSyslogEvent parser; crafted values containing = or backslash-escaped quotes can cause embedded keys such as srcip, dstip, date, time, and tz to remove or overwrite original top-level fields or produce an invalid message that Graylog discards. An unauthenticated network sender who can submit syslog messages can therefore manipulate security-log fields or evade logging to obscure malicious activity. This issue is fixed in Graylog Server versions 6.3.12, 7.0.7, and 7.1.2 and Graylog Forwarder version 7.3.

## Remediation

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

## Package advisory (CVE-2026-55841)

Affected packages:

- `org.graylog2:graylog2-server < 6.3.12`
- `org.graylog2:graylog2-server >= 7.0.0, < 7.0.7`
- `org.graylog2:graylog2-server >= 7.1.0, < 7.1.2`

Patched in:

- `org.graylog2:graylog2-server 6.3.12`
- `org.graylog2:graylog2-server 7.0.7`
- `org.graylog2:graylog2-server 7.1.2`

Source: https://github.com/advisories/GHSA-gqr6-r77p-c2pj