CVE-2026-27882 Coolify: Timing Attack in GitLab Webhook Token Validation
Attackers can exploit a timing side-channel in GitLab webhook validation to recover secret tokens, potentially bypassing authentication controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-27882?
CVE-2026-27882 is a medium-severity vulnerability in coollabsio coolify, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to 4.0.0-beta.461, the GitLab webhook endpoint uses a non-constant-time string comparison operator (!==) to validate the webhook secret token. This implementation is vulnerable to timing attacks, which could allow an attacker to gradually discover the secret token by measuring response time differences. This vulnerability is fixed in 4.0.0-beta.461.
Weakness: CWE-208
Which versions are affected by CVE-2026-27882?
How do I fix CVE-2026-27882?
No fix has been published for CVE-2026-27882 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-27882 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27882 exists.
Sources
Also known as GHSA-x525-46rq-mr8c.