Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Medium, CVSS 6.1amended

Oauthlib : Unsafe JSONP callback injection in RevocationEndpoint allows arbitrary JavaScript response generation

CVE-2026-49264GHSA-hj66-6f7g-4r5v

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (oauthlib 4.0.0), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • PyPI oauthlib

    Affected
    >= 0.6.1, <= 3.3.1
    Fixed in
    4.0.0

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
  • CVE-2026-49264: 0.23% estimated exploitation activity in the next 30 days; percentile 14.44 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Summary When enablejsonp=True, oauthlib's RevocationEndpoint reflects the user-supplied callback parameter directly into JavaScript response bodies on both success and error paths without validating that it is a legal JSONP callback name. This allows arbitrary JavaScript response generation instead of a restricted function call, making the documented JSONP revocation feature unsafe for browser-based JSONP consumption when attackers can influence callback. Details The issue is in oauthlib/oauth2/rfc6749/endpoints/revocation.py. When enablejsonp=True is passed to the RevocationEndpoint constructor, two code paths wrap the response body using the user-supplied request.callback parameter: The request.callback value comes from HTTP request parameters, either the query string or POST body, via the Request class in oauthlib/common.py (lines 394-395), which merges query and body parameters into params. Any value the client sends as callback is used verbatim. There is no validation of any…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-hj66-6f7g-4r5v

  2. Revision 2 · amended ·

    Amended from osv record GHSA-hj66-6f7g-4r5v

  3. Revision 1 · created ·

    Published from ghsa record GHSA-hj66-6f7g-4r5v

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-49264

Advisory: Oauthlib : Unsafe JSONP callback injection in RevocationEndpoint allows arbitrary JavaScript response generation
IDs: CVE-2026-49264, GHSA-hj66-6f7g-4r5v
Record: https://patchnext.com/advisories/cve-2026-49264 (revision 3, source checked 26 Oct 2026, 13:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: oauthlib 4.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI oauthlib: affected >= 0.6.1, <= 3.3.1; fixed in 4.0.0

## Suggested inspection (read-only)
- `python -m pip show oauthlib`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on oauthlib.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hj66-6f7g-4r5v (GitHub-reviewed advisory GHSA-hj66-6f7g-4r5v lists affected ranges: PyPI oauthlib >=0.6.1 <=3.3.1)
- Verified: https://osv.dev/vulnerability/GHSA-hj66-6f7g-4r5v (OSV record GHSA-hj66-6f7g-4r5v lists affected ranges: PyPI oauthlib >=0.6.1 <4.0.0 (fixed))

Commands are suggestions: review each one before running it.

Loading voting…