6.5

CVE-2024-31208: element-hq synapse

CVSS: 6.5v3.1MediumAnalyzed
AliasesGHSA-3h7q-rfh9-xm4vPYSEC-2024-50UBUNTU-CVE-2024-31208
Published 23-04-2024Last modified 13-02-2025
Open JSON

Vulnerability summary

CVE-2024-31208 is a medium (CVSS 6.5) vulnerability in element-hq synapse. EPSS estimates a 1.46% chance of exploitation in the next 30 days, higher than 73.2% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
1.46%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
USN-7444-1

Timeline

  1. 23-04-2024
    PublishedVulnerability first disclosed.
  2. 13-02-2025
    Last modifiedVulnerability information updated.

Description

Synapse is an open-source Matrix homeserver. A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in the V2 state resolution algorithm. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. Server administrators should upgrade to 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

1.46%

Chance of exploitation in the next 30 days

Percentile

73%

Versus all other CVEs

30-day change

0.00 pp

From 1.46% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.46%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu2 products
  • matrix-synapseAll versions (No fix recorded) | < 1.53.0-1ubuntu0.1~esm2
  • synapseAll versions (No fix recorded)
Debian1 product
  • matrix-synapse< 1.103.0-2
Element-hq1 product
Fedoraproject1 product
Matrix1 product
Opensuse1 product
  • matrix-synapse&distro=openSUSE Tumbleweed< 1.105.1-1.1
PyPI1 product
  • matrix-synapse< 55b0aa847a61774b6a3acdc4b177a20dc019f01a | < 1.105.1

7 vendors · 8 products

References

17 links
Show all 17 references