How severe is CVE-2019-11842?

CVE-2019-11842 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2019-11842 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-11842?

CVE-2019-11842 primarily affects Matrix Sydent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-11842?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-11842 published?

CVE-2019-11842 was published on 2019-05-09 and last updated on 2026-06-17.

CVE-2019-11842

CVE-2019-11842 is a high-severity vulnerability in Matrix Sydent with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-338
Affected product: Matrix Sydent
Published: 2019-05-09
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2019-11842?: 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.
How severe is CVE-2019-11842?: CVE-2019-11842 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2019-11842 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-11842?: CVE-2019-11842 primarily affects Matrix Sydent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-11842?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-11842 published?: CVE-2019-11842 was published on 2019-05-09 and last updated on 2026-06-17.

References

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/

Affected products (2)

cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:*
cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*

More vulnerabilities in Matrix Sydent

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