IdentityServer IdentityServer4 1.x before 1.5.3 and 2.x before 2.1.3 does not encode the redirect URI on the authorization response page, which might lead to XSS in some configurations.
IdentityServer IdentityServer4 through 2.4 has stored XSS via the httpContext to the host/Extensions/RequestLoggerMiddleware.cs LogForErrorContext method, which can be triggered by viewing a log.
IdentityServer3 2.4.x, 2.5.x, and 2.6.x before 2.6.1 has XSS in an Angular expression on the authorize response page, which might allow remote attackers to obtain sensitive information about the IdentityServer authorizat…