CVE-2026-52824 PoC — Kimai: Default APP_SECRET in Docker Image Enables Cookie Forgery and Account Takeover

Source

https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-52824.yaml

Associated Vulnerability

Title: Kimai: Default APP_SECRET in Docker Image Enables Cookie Forgery and Account Takeover (CVE-2026-52824)
Description:Kimai is an open-source time tracking application. Prior to 2.58.0, the official Docker image sets APP_SECRET to the public value change_this_to_something_unique in Dockerfile, and .docker/entrypoint.sh neither replaces nor rejects that value before Symfony uses it as kernel.secret. An unauthenticated attacker who reaches a deployment that did not override APP_SECRET, knows a username, correctly guesses the account ID associated with that username, and targets an account without active two-factor authentication can forge HMAC-protected authentication artifacts, including KIMAI_REMEMBER cookies and login links, to access the account without its password. The updated entrypoint generates and persists a random secret when no safe operator-provided value exists. This issue is fixed in version 2.58.0.

Description

Kimai Docker images <= 2.57.0 ship with a hardcoded APP_SECRET of "change_this_to_something_unique". This default secret is used by Symfony's SignatureHasher to HMAC-sign login links and remember-me cookies. An unauthenticated attacker who knows this default secret can forge valid authentication tokens and hijack any user account, including the super-admin.

File Snapshot

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