CVE-2025-30355
unknown
CVSS v3
—
CVSS v4 NEW
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VIR risk
—
Description
Synapse vulnerable to federation denial of service via malformed events
Predictions
Exploit likelihood
30%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| sid | Fixed | 1.121.0-6 |
| forky | Fixed | 1.121.0-6 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | matrix-synapse | <1.127.1 | 1.127.1 |
References
- https://github.com/element-hq/synapse/security/advisories/GHSA-v56r-hwv5-mxg6
- https://nvd.nist.gov/vuln/detail/CVE-2025-30355
- https://github.com/element-hq/synapse/commit/2277df2a1eb685f85040ef98fa21d41aa4cdd389
- https://github.com/element-hq/synapse
- https://github.com/element-hq/synapse/releases/tag/v1.127.1
- https://security-tracker.debian.org/tracker/CVE-2025-30355
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.