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Vulnerability · Published Jul 4, 2026 · Assigned by CPANSec

CVE-2026-12740Plack::Middleware::OAuth versions through 0.10 for Perl do not support the OAuth 2.0 state parameter

High 8.1

In plain English

A high-severity cross-site request forgery in Plack::Middleware::OAuth from CORNELIUS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.2%top 85.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Plack::Middleware::OAuth versions through 0.10 for Perl do not support the OAuth 2.0 state parameter. RequestTokenV2 builds the provider authorization redirect without issuing a state value, and AccessTokenV2 exchanges the callback code and registers the resulting token into the session (register_session) without verifying that the callback corresponds to an authorization request this session initiated. Any application that uses this middleware for OAuth 2.0 login is exposed to login cross-site request forgery: because the callback is not bound to the session that began the flow, an attacker who starts an authorization with their own provider account can deliver the resulting callback to a victim, causing the victim's session to complete the attacker's authorization and associating the attacker's provider identity and access token with that session. Where the application persists this as an account link, the attacker may retain access to the victim's account through their own provider credentials.

Affected products (as reported)

VendorProductVersions
CORNELIUS Plack::Middleware::OAuth 0 – through 0.10

Weakness: CWE-352 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

References