Open Redirect in Zoriya Kyoo
CVE-2026-77386
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.
Vulnerability class: Open Redirect
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (46.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Zoriya Kyoo — versions < 5.1.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-77386?
- CVE-2026-77386 is a medium-severity vulnerability in Zoriya Kyoo, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.5/10. Published 2026-09-18.
- How severe is CVE-2026-77386?
- Medium severity. CVSS v3 base score is 6.5 out of 10.