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Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M

CVE-2026-77386Kyoo: OIDC login token can be redirected to an attacker-controlled URL

Medium 6.5

In plain English

A medium-severity open redirect in Kyoo from zoriya. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.6%top 53.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Kyoo is a self-hosted media server focused on movies, series, and anime. Prior to 5.1.0, an unauthenticated attacker could initiate the OIDC login flow with an attacker-controlled redirectUrl. The login handling in auth/oidc.go stored that URL with the opaque login state, and /auth/oidc/logged/{provider} appended the provider, token, and error values before redirecting the victim's browser without validating the destination. Because the one-use token was not bound to the browser session that initiated login, an attacker who induced a victim to complete OIDC authentication could capture the token at the attacker-controlled destination and exchange it through /auth/oidc/callback/{provider} for the victim's Kyoo session. This issue is fixed in version 5.1.0.

Affected products (as reported)

VendorProductVersions
zoriya Kyoo < 5.1.0

Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

References