Upstream information

CVE-2020-26891 at MITRE

Description

AuthRestServlet in Matrix Synapse before 1.21.0 is vulnerable to XSS due to unsafe interpolation of the session GET parameter. This allows a remote attacker to execute an XSS attack on the domain Synapse is hosted on, by supplying the victim user with a malicious URL to the /_matrix/client/r0/auth/*/fallback/web or /_matrix/client/unstable/auth/*/fallback/web Synapse endpoints.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having moderate severity.

CVSS v2 Scores
CVSS detail National Vulnerability Database
Base Score 4.3
Vector AV:N/AC:M/Au:N/C:N/I:P/A:N
Access Vector Network
Access Complexity Medium
Authentication None
Confidentiality Impact None
Integrity Impact Partial
Availability Impact None
CVSS v3 Scores
CVSS detail National Vulnerability Database
Base Score 6.1
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Changed
Confidentiality Impact Low
Integrity Impact Low
Availability Impact None
CVSSv3 Version 3.1
SUSE Bugzilla entry: 1179186 [RESOLVED / FIXED]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
openSUSE Tumbleweed
  • matrix-synapse >= 1.43.0-1.1
 Patchnames:
openSUSE-Tumbleweed-2024-11041

SUSE Timeline for this CVE

CVE page created: Mon Oct 19 22:21:33 2020
CVE page last modified: Sat Nov 1 22:09:11 2025