OTP replay via incomplete TOTP consumption
Published Jul 3, 2026 · Updated Jul 3, 2026
Authentication bypass in Gitea 1.5.0 through 1.26.2 allows remote attackers to replay a captured TOTP code across HTTP authentication flows. Web handlers compare and update LastUsedPasscode in separate non-atomic database operations, while Basic Auth validates X-Gitea-OTP without consuming it. A victim password and live TOTP value are required; replay creates parallel authenticated sessions or enables API access that can mint a persistent token.
Summary
What happened
Authentication bypass in Gitea 1.5.0 through 1.26.2 allows remote attackers to replay a captured TOTP code across HTTP authentication flows. Web handlers compare and update LastUsedPasscode in separate non-atomic database operations, while Basic Auth validates X-Gitea-OTP without consuming it. A victim password and live TOTP value are required; replay creates parallel authenticated sessions or enables API access that can mint a persistent token.
The record
- CVE
- CVE-2026-20779
- Published
- Jul 3, 2026
- Updated
- Jul 3, 2026
- Vendor
- Gitea
- Product
- Gitea
- Classifications
- CWE-294, T1550
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 3, 2026CVE publishedPublication date reported by the CVE source.
- Jul 3, 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=1.5.0 <1.26.3
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
- Gitea TOTP replay proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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