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Fencer Intel
high 7.5

CVE-2019-11842 json

matrix-sydent and matrix-synapse Use Cryptographically Weak PRNG

published 7y ago modified 3mo ago also GHSA-gwf7-vfjf-wf6x , PYSEC-2019-185 , PYSEC-2026-2620 , EUVD-2019-0082

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

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.

Patch / fix

  • pypi matrix-sydent 1.0.3
  • pypi matrix-synapse 0.99.3.1
  • matrix sydent 1.0.3
  • matrix synapse 0.99.3.1
  • matrix-synapse Ubuntu Pro 18.04 LTS 0.24.0+dfsg-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2019-11842

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Exploit prediction

1.80% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi matrix-sydent
<1.0.3
1.0.3
pypi matrix-synapse
<0.99.3.1
0.99.3.1

Classification

Weakness
  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.