Login CSRF via missing OAuth state validation
Published Jul 4, 2026 · Updated Jul 4, 2026
Cross-site request forgery in Plack::Middleware::OAuth 0.10 and earlier allows remote attackers to bind OAuth tokens to victim sessions. RequestTokenV2 omits a state value from authorization redirects, while AccessTokenV2 accepts callback codes and registers tokens without matching an initiating session request. Exploitation requires a victim to follow an attacker-supplied callback; the session then carries the attacker's provider identity, and persistent account linking can preserve access.
Summary
What happened
Cross-site request forgery in Plack::Middleware::OAuth 0.10 and earlier allows remote attackers to bind OAuth tokens to victim sessions. RequestTokenV2 omits a state value from authorization redirects, while AccessTokenV2 accepts callback codes and registers tokens without matching an initiating session request. Exploitation requires a victim to follow an attacker-supplied callback; the session then carries the attacker's provider identity, and persistent account linking can preserve access.
The record
- CVE
- CVE-2026-12740
- Published
- Jul 4, 2026
- Updated
- Jul 4, 2026
- Vendor
- Yo-An Lin
- Product
- Plack::Middleware::OAuth
- Classifications
- CWE-352, CAPEC-62, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 4, 2026CVE publishedPublication date reported by the CVE source.
- Jul 4, 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?
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- Affected versionversion=0 <=0.10
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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Your stack
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