Webhook token disclosure via early-exit comparison
Published Jun 30, 2026 · Updated Jun 30, 2026
Observable timing discrepancy in Coolify before 4.0.0-beta.461 allows remote attackers to recover GitLab webhook tokens. The GitLab webhook controller compares the configured secret with the X-Gitlab-Token header using PHP's early-exit !== operator, exposing prefix-match timing differences. Exploitation requires the repository name, network access, and sufficiently stable latency; a recovered token permits forged webhook events and unauthorized deployments.
Summary
What happened
Observable timing discrepancy in Coolify before 4.0.0-beta.461 allows remote attackers to recover GitLab webhook tokens. The GitLab webhook controller compares the configured secret with the X-Gitlab-Token header using PHP's early-exit !== operator, exposing prefix-match timing differences. Exploitation requires the repository name, network access, and sufficiently stable latency; a recovered token permits forged webhook events and unauthorized deployments.
The record
- CVE
- CVE-2026-27882
- Published
- Jun 30, 2026
- Updated
- Jun 30, 2026
- Vendor
- coolLabs
- Product
- Coolify
- Classifications
- CWE-208, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 30, 2026CVE publishedPublication date reported by the CVE source.
- Jun 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.0.0-beta.461
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitLab webhook token timing-attack proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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