CVE-2026-52824

CRITICALPre-NVD 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: —CVSS: —Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Kimai: Default APP_SECRET in Docker Image Enables Cookie Forgery and Account Takeover

Summary

The official Kimai Docker image ships with APP_SECRET=change_this_to_something_unique as the default environment variable. The Docker entrypoint does not override or validate this value. Any Kimai instance deployed using the Docker image without explicitly setting APP_SECRET runs with a publicly-known Symfony kernel.secret, enabling an unauthenticated attacker to forge HMAC-signed cookies and login links to take over any account including super_admin.

Details

Dockerfile:263 sets ENV APP_SECRET=change_this_to_something_unique. This value is consumed by config/packages/framework.yaml:7 as kernel.secret, which Symfony uses to HMAC-sign:

  • The KIMAI_REMEMBER remember-me cookie
  • LoginLink signatures
  • Password reset URLs
  • CSRF tokens

The .docker/entrypoint.sh does not check for or replace the default sentinel value. The bare-metal .env.dist:38 ships the same default. No startup-time guard exists anywhere in the codebase that refuses to start when APP_SECRET equals the sentinel.

User IDs are sequential integers starting from 1. The first super_admin account is almost always id=1. User IDs are visible in some URLs and API responses.

*A PoC was provided, but removed for security reasons.*

Impact

Any Kimai instance deployed via the official Docker image without overriding APP_SECRET can be compromised from the internet. An unauthenticated attacker who can reach the Kimai URL can forge authentication tokens and log in as any user if:

  • a username is known AND
  • the correct account ID for this username is guessed AND
  • the account has no active 2FA (two factor) authentication

Solution

  • The entrypoint.sh file is updated and now contains a script that generates a random APP_SECRET via bin2hex(random_bytes(32)) which will be stored in /opt/kimai/var/data/.appsecret
  • The entrypoint.sh will create the file /opt/kimai/.env.local containing the APP_SECRET, either fetched from the Docker Environment or from the newly created secret file
  • The documentation was updated to highlight the importance of using a random secret for APP_SECRET
  • The Dockerfile removed default APP_SECRET=change_this_to_something_unique
  • Login links now contain more entropy (see GHSA-m492-gv72-xvxj) - so even without all previous changes, attackers won't be able to generate Login links even for installations that have a hard-coded APP_SECRET=change_this_to_something_unique

See https://www.kimai.org/en/security/ghsa-jr9p-4h4j-6c58 for more information.

CVSS v3
—
EG Score
0.0(none)
EPSS
—
KEV
Not listed

Published

July 14, 2026

Last Modified

July 14, 2026

Vendor Advisories for CVE-2026-52824(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 1× in last 7d / 1× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-14 00:25 UTCEG score recompute

Frequently asked(3)

What is CVE-2026-52824?
CVE-2026-52824 is a critical vulnerability published on July 14, 2026. Kimai: Default APP_SECRET in Docker Image Enables Cookie Forgery and Account Takeover Summary The official Kimai Docker image ships with APPSECRET=changethistosomethingunique as the default environment variable. The Docker entrypoint does not override or validate this value. Any Kimai instance…
When was CVE-2026-52824 disclosed?
CVE-2026-52824 was first published in the National Vulnerability Database on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
How do I remediate CVE-2026-52824?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52824, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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