CVE-2020-26890

Published Nov 24, 2020 CVSS 3.1 · 7.5 High EPSS 3.0% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2020-0107 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.
Github GHSA Github GHSA GHSA-4mp3-385r-v63f Denial of service attack due to invalid JSON
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 4, 2024, 4:03 PM
Reserved
Oct 8, 2020, 12:00 AM
Status
Modified
Published
Nov 24, 2020, 3:15 AM
Modified
Jun 17, 2026, 3:08 AM