id: PYSEC-2026-2620
published: "2026-07-09T16:49:47.132995Z"
modified: "2026-07-09T16:49:47.132995Z"
aliases:
- CVE-2019-11842
- GHSA-gwf7-vfjf-wf6x
summary: matrix-sydent and matrix-synapse Use Cryptographically Weak PRNG
details: 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.
affected:
- package:
    name: matrix-sydent
    ecosystem: PyPI
    purl: pkg:pypi/matrix-sydent
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 1.0.3
references:
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2019-11842
- type: ADVISORY
  url: https://github.com/advisories/GHSA-gwf7-vfjf-wf6x
- type: WEB
  url: https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2019-185.yaml
- type: WEB
  url: https://matrix.org/blog/2019/05/03/security-updates-sydent-1-0-3-synapse-0-99-3-1-and-riot-android-0-9-0-0-8-99-0-8-28-a
- type: PACKAGE
  url: https://pypi.org/project/matrix-sydent
severity:
- type: CVSS_V3
  score: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- type: CVSS_V4
  score: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N