Distribution advisory
This page covers CVE-2025-30355 as tracked by Ubuntu, for the package matrix-synapse. No fixed version has been recorded for this distribution yet.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: None.
- Availability impact: High — total loss, or loss the attacker controls.
Weakness class
UBUNTU-CVE-2025-30355 is classified as CWE-20: Improper Input Validation. The application accepts input without checking that it has the expected form, so malformed values reach code that assumes they are well formed.
Affected software
UBUNTU-CVE-2025-30355 is recorded against 1 package.
Timeline and source
Published on 27 March 2025 and last revised on 24 October 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
github.com (Report)
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-20: Improper Input Validation) in other software:
