---
title: "CVE-2026-52824: Kimai: Default APP_SECRET in Docker Image Enables Cookie Forgery and Account Takeover"
url: https://erroneo.us/security/cve/CVE-2026-52824/
description: "CVE-2026-52824 (kimai/kimai (Composer (PHP))): Kimai is an open-source time tracking application. Prior to 2.58.0, the official Docker image sets APPSECRET…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-15
date_modified: 2026-09-16
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-52824"
kev: false
cvss: 9.1
epss: 0.01333
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.3% , percentile 71: FIRST’s model estimates a 1.3% chance of exploitation activity in the next 30 days, higher than 71% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes kimai/kimai (Composer (PHP)) <= 2.57.0, fixed in 2.58.0 . Check your lockfile, including transitive dependencies.

## What it is

Kimai is an open-source time tracking application. Prior to 2.58.0, the official Docker image sets APPSECRET to the public value changethistosomethingunique 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 APPSECRET, 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 KIMAIREMEMBER 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.

## Affected packages

- Composer (PHP) `kimai/kimai` <= 2.57.0 → fixed: 2.58.0

## Affected products (CVE record)

- kimai kimai: < 2.58.0

## Severity

- GitHub_M CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`
- GitHub CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.33% probability of exploitation activity in the next 30 days; percentile 71.

## Sources

- [GitHub Advisory GHSA-jr9p-4h4j-6c58](https://github.com/advisories/GHSA-jr9p-4h4j-6c58)
- [CVE.org record CVE-2026-52824](https://www.cve.org/CVERecord?id=CVE-2026-52824)
- [NVD entry CVE-2026-52824](https://nvd.nist.gov/vuln/detail/CVE-2026-52824)
- [github.com](https://github.com/kimai/kimai/security/advisories/GHSA-jr9p-4h4j-6c58)
- [github.com](https://github.com/kimai/kimai/pull/5952)
- [github.com](https://github.com/kimai/kimai/commit/31a8f887a5cda517db7b4320a7ad997c87d08601)
- [github.com](https://github.com/kimai/kimai/releases/tag/2.58.0)
- [kimai.org](https://www.kimai.org/en/security/ghsa-jr9p-4h4j-6c58)

---
Source page: https://erroneo.us/security/cve/CVE-2026-52824/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt