Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2025-61672 — matrix-synapse

⚪ Unknown ✅ No Known Exploit CWE-1287 NVD
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Synapse's invalid device keys degrade federation functionality

Impact

Lack of validation for device keys in Synapse before 1.138.3 and in Synapse 1.139.0 allow an attacker registered on the victim homeserver to degrade federation functionality, unpredictably breaking outbound federation to other homeservers.

Patches

Patched in Synapse 1.138.3, 1.138.4, 1.139.1, and 1.139.2.

Note that even though 1.138.3 and 1.139.1 fix the vulnerability, they inadvertently introduced an unrelated regression. For this reason, it is recommend to skip these releases and upgrading straight to 1.138.4 and 1.139.2.

Workarounds

The vulnerability can only be exploited by users registered on the victim homeserver.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. Rated impact: confidentiality none, integrity low, availability low.

CVSS metrics in full

The score comes from this vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Attack requirements: None — no deployment-specific condition has to hold.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Confidentiality impact: None.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: Low — limited, and the attacker does not choose what is affected.

Weakness class

CVE-2025-61672 is classified as CWE-1287: Improper Validation of Specified Type of Input. The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.

Affected software

CVE-2025-61672 is recorded against 2 packages.

  • matrix-synapse (from 1.139.0rc2 up to 1.139.1)
  • unknown

Timeline and source

Published on 7 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Package)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
pypi.org (Package)
github.com (Advisory)

Other advisories for this package

matrix-synapse has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-1287: Improper Validation of Specified Type of Input) in other software:

CVE-2025-61672 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
CWE CWE-1287
Public Exploit ✅ No
Source NVD
Published 2026-07-07
Updated 2026-08-20
Modified 2026-07-07
Fix URL N/A

Affected Packages

Software From version Fixed in
matrix-synapse 1.139.0rc2 1.139.1
unknown — —

Free Vulnerability Check

Is your site affected by CVE-2025-61672?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2025-61672 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2025
✓