Upstream information

CVE-2025-61920 at MITRE

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.5, Authlib's JOSE implementation accepts unbounded JWS/JWT header and signature segments. A remote attacker can craft a token whose base64url-encoded header or signature spans hundreds of megabytes. During verification, Authlib decodes and parses the full input before it is rejected, driving CPU and memory consumption to hostile levels and enabling denial of service. Version 1.6.5 patches the issue. Some temporary workarounds are available. Enforce input size limits before handing tokens to Authlib and/or use application-level throttling to reduce amplification risk.

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (GitHub) SUSE
Base Score 7.5 7.5
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network Network
Attack Complexity Low Low
Privileges Required None None
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None None
Integrity Impact None None
Availability Impact High High
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail SUSE
Base Score 8.7
Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
SUSE Bugzilla entry: 1251921 [NEW]

No SUSE Security Announcements cross referenced.

List of packages in QA

Product(s) Package(s)
SUSE Linux Enterprise Module for Python 3 15 SP6
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Server 15 SP6
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Desktop 15 SP6
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Server for SAP Applications 15 SP6
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise High Performance Computing 15 SP6
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Module for Python 3 15 SP7
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Server 15 SP7
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Desktop 15 SP7
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise Server for SAP Applications 15 SP7
  • python311-Authlib >= 1.3.1-150600.3.6.1
SUSE Linux Enterprise High Performance Computing 15 SP7
  • python311-Authlib >= 1.3.1-150600.3.6.1

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP6 python-Authlib In progress
SUSE Linux Enterprise Desktop 15 SP7 python-Authlib In progress
SUSE Linux Enterprise High Performance Computing 15 SP6 python-Authlib In progress
SUSE Linux Enterprise High Performance Computing 15 SP7 python-Authlib In progress
SUSE Linux Enterprise Module for Python 3 15 SP6 python-Authlib In progress
SUSE Linux Enterprise Module for Python 3 15 SP7 python-Authlib In progress
SUSE Linux Enterprise Server 15 SP6 python-Authlib In progress
SUSE Linux Enterprise Server 15 SP7 python-Authlib In progress
SUSE Linux Enterprise Server for SAP Applications 15 SP6 python-Authlib In progress
SUSE Linux Enterprise Server for SAP Applications 15 SP7 python-Authlib In progress
openSUSE Leap 15.6 python-Authlib Affected

SUSE Timeline for this CVE

CVE page created: Sat Oct 11 00:00:43 2025
CVE page last modified: Mon Oct 13 22:35:26 2025