DEBIAN-CVE-2026-49265
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-49265
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49265.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-49265
- Upstream
- Published
- 2026-10-13T16:17:20Z
- Modified
- 2026-10-14T15:00:11Z
- Severity
-
- 6.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N CVSS Calculator
- Summary
- [none]
- Details
-
OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 3.0.0 until 4.0.0, OAuthLib's PKCE checks in oauthlib/oauth2/rfc6749/grant_types/authorization_code.py compare attacker-supplied code_verifier values with stored challenges using ordinary string equality in code_challenge_method_plain and code_challenge_method_s256. Because the comparison can return after a length difference or the first mismatching character, repeated token endpoint measurements can reveal common-prefix timing information that could potentially allow recovery of the code_verifier, unauthorized access-token acquisition, and account takeover. Practical exploitation requires an intercepted, single-use authorization code and enough measurements to overcome real-world network noise; the local timing benchmark does not establish practical remote account takeover, so the weakness remains a defense-in-depth concern. This issue is fixed in version 4.0.0.
- References
Affected packages
Debian:12 / python-oauthlib
Package
- Name
- python-oauthlib
- Purl
- pkg:deb/debian/python-oauthlib?arch=source&distro=bookworm
Debian:13 / python-oauthlib
Package
- Name
- python-oauthlib
- Purl
- pkg:deb/debian/python-oauthlib?arch=source&distro=trixie
Debian:14 / python-oauthlib
Package
- Name
- python-oauthlib
- Purl
- pkg:deb/debian/python-oauthlib?arch=source&distro=forky