CVE-2026-49264
OAuthLib: Unsafe JSONP callback injection in RevocationEndpoint allows arbitrary JavaScript response generation
Description
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.
INFO
Published Date :
Oct. 13, 2026, 4:17 p.m.
Last Modified :
Oct. 16, 2026, 11:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | github | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Validate callback parameter against allowed JavaScript identifier patterns.
- Reject callbacks that do not match the allowed pattern.
- Set Content-Type to application/javascript when JSONP is enabled.
- Consider deprecating JSONP in favor of CORS.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49264.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49264 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49264
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-49264 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49264 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 16, 2026
Action Type Old Value New Value Added Reference https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v Added SSVC {'id': 'CVE-2026-49264', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-16T22:04:19.260810Z'} -
New CVE Received by [email protected]
Oct. 13, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/49xxx/CVE-2026-49264.json">CVE-2026-49264</a> Added Reference https://github.com/oauthlib/oauthlib/commit/c888359f3c42bec235b2c5caab2069c9ed62457c Added Reference https://github.com/oauthlib/oauthlib/pull/951 Added Reference https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0 Added Reference https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v