CVE-2025-46827: Graylog2 server Graylog Allows Session Takeover Vulnerability

HIGH
Advisory Identifier: GHSA-76vf-mpmx-777j
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CVSS 8.0
CWE-79
Published
Advisory Summary

CVE-2025-46827 is a HIGH (CVSS 8.0) graylog allows session takeover vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Graylog2 server libraries in the Maven ecosystem. The issue involves graylog allows session takeover via insufficient html sanitization. Remediation is available by upgrading affected packages to version 6.0.14, 6.1.10.

CVE-2025-46827 at a Glance

CVE Identifier CVE-2025-46827
GHSA Identifier GHSA-76vf-mpmx-777j
Severity HIGH
CVSS v3.1 Base Score 8.0
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Graylog2 server
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-46827

To remediate this vulnerability, upgrade all affected Graylog2 server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.graylog2:graylog2-server fixed: 6.0.14 
<dependency>
    <groupId>org.graylog2</groupId>
    <artifactId>graylog2-server</artifactId>
    <version>6.0.14</version>
</dependency>
org.graylog2:graylog2-server fixed: 6.1.10 
<dependency>
    <groupId>org.graylog2</groupId>
    <artifactId>graylog2-server</artifactId>
    <version>6.1.10</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.graylog2

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2025-46827, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.graylog2

Analyze the terminal output to locate any version of Graylog2 server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.0.14), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.graylog2 command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Graylog2 server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact It is possible to obtain user session cookies by submitting an HTML form as part of an Event Definition Remediation Step field. For this attack to succeed, the attacker needs a user account with permissions to create event definitions, while the user must have permissions to view alerts. Additionally, an active Input must be present on the Graylog server that is capable of receiving form data (e.g. a HTTP input, TCP raw or syslog etc). ### Patches ### Workarounds None, as long as the relatively rare prerequisites are met. Analysis provided by Fabian Yamaguchi - Whirly Labs (Pty) Ltd

CVE-2025-46827 Affected Graylog2 server Versions

2 component(s)
Fixed Versions:
6.0.146.1.10
Product / Package Ecosystem Affected Versions Fixed Version
org.graylog2:graylog2-server
maven/org.graylog2/graylog2-server
Maven
< 6.0.14
6.0.14
org.graylog2:graylog2-server
maven/org.graylog2/graylog2-server
Maven
≥ 6.1.0
< 6.1.10
6.1.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-76vf-mpmx-777j
NVD — CVE-2025-46827 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-46827
Graylog2 server Source Repository REPOSITORY
https://github.com/Graylog2/graylog2-server

Frequently Asked Questions

What is CVE-2025-46827?
CVE-2025-46827 is a security vulnerability in Graylog2 server involving Graylog Allows Session Takeover via Insufficient HTML Sanitization under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Graylog2 server versions are affected?
Affected versions include releases prior to 6.0.14, 6.1.10 across affected packages: org.graylog2:graylog2-server.
What version fixes CVE-2025-46827?
Upgrading to 6.0.14, 6.1.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is graylog2-server affected?
Yes, org.graylog2:graylog2-server is affected in releases prior to 6.0.14, 6.1.10. Upgrade your dependency to 6.0.14, 6.1.10 or later.
What is the CVSS score of CVE-2025-46827?
CVE-2025-46827 has a CVSS v3.1 base score of 8.0 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-46827?
CVE-2025-46827 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2025-46827?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.graylog2'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-76vf-mpmx-777j",
  "modified" : "2025-05-07T19:08:39Z",
  "published" : "2025-05-07T15:27:24Z",
  "aliases" : [ "CVE-2025-46827" ],
  "summary" : "Graylog Allows Session Takeover via Insufficient HTML Sanitization",
  "details" : "### Impact\nIt is possible to obtain user session cookies by submitting an HTML form as part of an Event Definition Remediation Step field. \nFor this attack to succeed, the attacker needs a user account with permissions to create event definitions, while the user must have permissions to view alerts. Additionally, an active Input must be present on the Graylog server that is capable of receiving form data (e.g. a HTTP input, TCP raw or syslog etc).\n\n### Patches\n\n### Workarounds\nNone, as long as the relatively rare prerequisites are met.\n\nAnalysis provided by Fabian Yamaguchi - Whirly Labs (Pty) Ltd",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.graylog2:graylog2-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.0.14"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.0.13"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.graylog2:graylog2-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.1.0"
      }, {
        "fixed" : "6.1.10"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.1.9"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-76vf-mpmx-777j"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-46827"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Graylog2/graylog2-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-05-07T15:27:24Z",
    "nvd_published_at" : "2025-05-07T16:15:22Z"
  }
}