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🐍 PyPI

CVE-2019-11842

HIGH

CVE-2019-11842 is a high-severity (CVSS 7.5) CWE-338 vulnerability in matrix-sydent. O3 Security confirms whether CVE-2019-11842 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

matrix-sydent and matrix-synapse Use Cryptographically Weak PRNG

Also known asGHSA-gwf7-vfjf-wf6xPYSEC-2019-185PYSEC-2026-2620
Published
May 9, 2019
Updated
Jul 13, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed

Blast Radius

2 pkgs affected
🐍matrix-sydent🐍matrix-synapse

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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 Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPImatrix-sydentall versions1.0.3
🐍PyPImatrix-synapseall versions0.99.3.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-sydent. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update matrix-sydent to 1.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11842 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2019-11842 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2019-11842. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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.
O3 Security · Impact-Aware SCA

Is CVE-2019-11842 in your dependencies?

O3 detects CVE-2019-11842 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.