An issue was discovered in Matrix Sydent before 1.0.3 and Synapse before 0.99.3.1.
Priority LOW 36CWE-338Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and GitHub.
Summary
An issue was discovered in Matrix Sydent before 1.0.3 and Synapse before 0.99.3.1. Random number generation is mishandled, which makes it easier for attackers to predict a Sydent authentication token or a Synapse random ID.
Why it matters now
EPSS 0.01795 78th percentileScored 2026-11-07
Fix Fixed matrix-sydent (PyPI): 1.0.3matrix-synapse (PyPI): 0.99.3.1
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | matrix-sydent (PyPI) | before 1.0.3 | 1.0.3 | Patch available | GHSA-gwf7-vfjf-wf6x |
| — | matrix-synapse (PyPI) | before 0.99.3.1 | 0.99.3.1 | Patch available | GHSA-gwf7-vfjf-wf6x |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- matrix-sydent (PyPI) Vendor— Affected before 1.0.3 Fixed in 1.0.3 Patch available GHSA-gwf7-vfjf-wf6x
- matrix-synapse (PyPI) Vendor— Affected before 0.99.3.1 Fixed in 0.99.3.1 Patch available GHSA-gwf7-vfjf-wf6x
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:* | before 1.0.3 | Vulnerable | matrix-org |
| cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* | before 0.99.3.1 | Vulnerable | matrix-org |
- cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:* Versions before 1.0.3 Vulnerable ·matrix-org
- cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* Versions before 0.99.3.1 Vulnerable ·matrix-org
Remediation
- Fix · GHSA-gwf7-vfjf-wf6x matrix-sydent (PyPI) Fixed in 1.0.3 Advisory →
- Fix · GHSA-gwf7-vfjf-wf6x matrix-synapse (PyPI) Fixed in 0.99.3.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2019-11842
- 2026-10-03 Alias added: GHSA-gwf7-vfjf-wf6x
References
Advisory 3
More matrix-org Sydent vulnerabilities
- TI-2023-20035 Sydent does not verify email server certificates CVSS 3.1CRITICAL 9.3
- TI-2021-10144 SSRF in Sydent due to missing validation of hostnames CVSS 3.1HIGH 7.7
- TI-2021-10143 Denial of service attack via memory exhaustion CVSS 3.1HIGH 7.5
- TI-2019-08469 util/emailutils.py in Matrix Sydent before 1.0.2 mishandles registration restrictions… CVSS 3.0MEDIUM 5.9
- TI-2021-10145 Malicious users could control the content of invitation emails CVSS 3.1MEDIUM 5.7
- TI-2021-10146 Denial of service (via resource exhaustion) due to improper input validation CVSS 3.1MEDIUM 4.3
Sources
- CVE-2019-11842 · CVE Program
- CVE-2019-11842 · NVD
- FIRST EPSS
- GHSA-gwf7-vfjf-wf6x · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences