CVE-2025-46827: Graylog Allows Session Takeover via Insufficient HTML Sanitization
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
Other sources
Graylog is a free and open log management platform. Prior to versions 6.0.14, 6.1.10, and 6.2.0, 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). Versions 6.0.14, 6.1.10, and 6.2.0 fix the issue. No known workarounds are available, as long as the relatively rare prerequisites are met.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-46827?
CVE-2025-46827 has been classified with a high severity due to its potential for session cookie theft.
How do I fix CVE-2025-46827?
To resolve CVE-2025-46827, update the graylog2-server package to version 6.1.10 or 6.0.14.
What versions are affected by CVE-2025-46827?
CVE-2025-46827 affects graylog2-server versions from 6.1.0 to 6.1.9 and up to 6.0.13.
Who can exploit CVE-2025-46827?
An attacker with a user account that has permissions to create event definitions can exploit CVE-2025-46827.
What is the impact of CVE-2025-46827?
The impact of CVE-2025-46827 allows attackers to obtain user session cookies through a crafted HTML form.