CVE-2025-61672 (GCVE-0-2025-61672)
Vulnerability from cvelistv5 – Published: 2025-10-08 14:55 – Updated: 2025-10-15 16:11
VLAI
EPSS
VEX
Title
Synapse: Invalid device keys degrade federation functionality
Summary
Synapse is an open source Matrix homeserver implementation. 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. The issue is 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, the maintainers of Synapse recommend skipping these releases and upgrading straight to 1.138.4 and 1.139.2.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-10-15 16:10 UTC
CWE
- CWE-1287 - Improper Validation of Specified Type of Input
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/element-hq/synapse/security/ad… | x_refsource_CONFIRM |
| https://github.com/element-hq/synapse/pull/17097 | x_refsource_MISC |
| https://github.com/element-hq/synapse/commit/26aa… | x_refsource_MISC |
| https://github.com/element-hq/synapse/commit/7069… | x_refsource_MISC |
| https://github.com/element-hq/synapse/releases/ta… | x_refsource_MISC |
| https://github.com/element-hq/synapse/releases/ta… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| element-hq | synapse |
Affected:
< 1.138.3
Affected: = 1.139.0 |
guessed |
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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