CVEvulnerability

CVE-2020-26890

7.5 HIGH Published 2020-11-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-11-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:N/A:P
Weaknesses
CWE-20

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.

Affected configurations

• matrix synapse (< 1.20.0) • fedoraproject fedora 32 • fedoraproject fedora 33

Related

Weakness · CWE (1)

  • CWE-20 Improper Input Validation weakness

References