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Fencer Intel
medium 4.8

CVE-2026-27882 json

Coolify: Timing Attack in GitLab Webhook Token Validation

published 4mo ago modified 15d ago also EUVD-2026-40328

cvss
4.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

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.

Patch / fix

  • coollabs coolify 4.0.0-beta.461

Is CVE-2026-27882 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/coollabsio/coolify/security/advisories/GHSA-x525-46rq-mr8c referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

  • coollabsio coolify

Classification

Weakness
  • CWE-208 Observable Timing Discrepancy

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.