CVE-2020-26890

Severity CVSS v4.0:
Pending analysis
Type:
CWE-20 Input Validation
Publication date:
24/11/2020
Last modified:
07/11/2023

Description

Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into the room's state, the impact is long-lasting and is not fixed by an upgrade to a newer version, requiring the event to be manually redacted instead. Since events are replicated to servers of other room members, the impact is not constrained to the server of the event sender.

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* 1.20.0 (excluding)
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*