---
id: CVE-2026-49264
title: >-
  OAuthLib is an implementation of the OAuth request-signing logic for Python
  3.6+
summary: >-
  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…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: oauthlib
product: oauthlib
affected:
  - 'oauthlib >= 0.6.1, <= 3.3.1'
patched:
  - oauthlib 4.0.0
published: '2026-10-13'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T23:17:01.890'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-49264'
references:
  - url: >-
      https://github.com/oauthlib/oauthlib/commit/c888359f3c42bec235b2c5caab2069c9ed62457c
    label: security-advisories@github.com
  - url: 'https://github.com/oauthlib/oauthlib/pull/951'
    label: security-advisories@github.com
  - url: 'https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v
    label: security-advisories@github.com
  - url: >-
      https://github.com/oauthlib/oauthlib/security/advisories/GHSA-hj66-6f7g-4r5v
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-49264'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/oauthlib/PYSEC-2026-4113.yaml
  - url: 'https://github.com/advisories/GHSA-hj66-6f7g-4r5v'
  - url: 'https://github.com/oauthlib/oauthlib'
  - url: 'https://pypi.org/project/oauthlib'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49264.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-49264'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2550287'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-49264'
  - url: 'https://access.redhat.com/errata/RHSA-2026:82415'
  - url: 'https://access.redhat.com/errata/RHSA-2026:82368'
tags:
  - nvd
  - ghsa
  - pip
  - osv
  - csaf
  - vex
  - red-hat
  - cve.org
  - exploit-available
epss: 0.00234
epssPercentile: 0.14285
aliases:
  - GHSA-hj66-6f7g-4r5v
  - PYSEC-2026-4113
ecosystem: pip
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-16T22:04:19.260810Z'
ingestedAt: '2026-09-29T18:42:35.834Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-49264)

Affected packages:

- `oauthlib >= 0.6.1, <= 3.3.1`

Patched in:

- `oauthlib 4.0.0`

Source: https://github.com/advisories/GHSA-hj66-6f7g-4r5v

## Vendor advisories

- **RHSA-2026:82415** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82415)
- **RHSA-2026:82368** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82368)
- **Red Hat VEX** · Moderate · affected: Confidential Compute Attestation, Fence Agents Remediation Operator, Lightspeed Core, Lightspeed Services for Advanced Cluster Management, Migration Toolkit for Applications 8, Migration Toolkit for Containers, … · no fix planned: Confidential Compute Attestation, Fence Agents Remediation Operator, Lightspeed Core, Lightspeed Services for Advanced Cluster Management, … · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49264.json)