CVE-2026-49264
Oauthlib : Unsafe JSONP callback injection in RevocationEndpoint allows arbitrary JavaScript response generation
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | oauthlib | >= 0.6.1, <= 3.3.1 | 4.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-hj66-6f7g-4r5v
- https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v
- https://github.com/oauthlib/oauthlib/pull/951
- https://github.com/oauthlib/oauthlib/commit/c888359f3c42bec235b2c5caab2069c9ed62457c
- https://nvd.nist.gov/vuln/detail/CVE-2026-49264
- https://github.com/pypa/advisory-database/tree/main/vulns/oauthlib/PYSEC-2026-4113.yaml
- https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0