CVE-2026-118669
OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+
- Risk score
- 60/100
- CVSS
- 8.4 v4.0
- Published
- 28 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. Prior to 4.0.0, the client_credentials and Resource Owner Password Credentials token grant handlers can authenticate request.client as one confidential client while retaining an attacker-supplied request.client_id for validate_grant_type…
- Affected
- See advisory
- Fix
- Upgrade the product to 4.0.0 or later.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 8.4 high
- On your watchlist: python
References
Original description
OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. Prior to 4.0.0, the client_credentials and Resource Owner Password Credentials token grant handlers can authenticate request.client as one confidential client while retaining an attacker-supplied request.client_id for validate_grant_type and validate_scopes. A lower-privilege authenticated client can therefore cause grant and scope authorization to use another client's identity when an application validator relies on the documented client_id argument, potentially issuing tokens with unauthorized grants or scopes. Validators that authorize exclusively from request.client may not be affected. This issue is fixed in version 4.0.0.
Last activity 28 Oct 2026. Patch Forecast updates every hour.