CVE-2026-49264
OAuthLib: Unsafe JSONP callback injection in RevocationEndpoint allows arbitrary JavaScript response generation
OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 0.6.1 until 4.0.0, OAuthLib's RevocationEndpoint in oauthlib/oauth2/rfc6749/endpoints/revocation.py reflects an unvalidated callback request parameter into success and error response bodies when enable_jsonp=True. The callback can come from the query string or request body and is used without restricting it to a legal JavaScript function name. A browser application that loads the revocation response as trusted JSONP and permits attacker influence over callback can therefore execute attacker-controlled JavaScript in the including application's origin, with access to its DOM and script-accessible data. The feature is disabled by default, so only deployments that explicitly enable JSONP are affected. This issue is fixed in version 4.0.0.
- Affected
- oauthlib
- CVSS v3.1 GITHUB
- 6.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS
- 0.31% chance of exploitation in the next 30 days, 23rd percentile
- Published
- 2026-10-13
- Updated
- 2026-10-16