CVE-2026-63398
Coop is an open source review and moderation tool from ROOST
- Risk score
- 44/100
- CVSS
- 7.4 v4.0
- Published
- 30 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Coop is an open source review and moderation tool from ROOST. Prior to 1.0.2, the SAML strategy's verify callback resolved the authenticated user by email alone using kyselyUserFindByEmail, without binding the lookup to the organization in /saml/login/:orgId/callback. An attacker who administers an organization and co…
- Affected
- See advisory
- Fix
- Upgrade the product to 1.0.2 or later.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.4 high
References
Original description
Coop is an open source review and moderation tool from ROOST. Prior to 1.0.2, the SAML strategy's verify callback resolved the authenticated user by email alone using `kyselyUserFindByEmail`, without binding the lookup to the organization in `/saml/login/:orgId/callback`. An attacker who administers an organization and controls its SAML IdP signing key can submit an assertion for a victim email to another organization's callback when that target organization has registered the same signing certificate. The assertion verifies against the target certificate, and the email resolves to the target user, creating a session as that user and allowing full cross-tenant account takeover without privileges in the target organization. Exploitation requires the unusual configuration in which the target certificate matches a signing key controlled by the attacker. This issue is fixed in version 1.0.2.
Last activity 30 Oct 2026. Patch Forecast updates every hour.