CVE-2026-49264
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.
- CVSS 3.1
- 6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-25)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-hj66-6f7g-4r5v | PyPI | oauthlib | >=0.6.1 <4.0.0 | 4.0.0 |
| PYSEC-2026-4113 | PyPI | oauthlib | >=0.6.1 <4.0.0 | 4.0.0 |
References
- https://github.com/oauthlib/oauthlib/commit/c888359f3c42bec235b2c5caab2069c9ed62457c
- https://github.com/oauthlib/oauthlib/pull/951
- https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0
- https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v
- https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v