What is CVE-2019-12743?

CVE-2019-12743 is a medium-severity vulnerability in Humhub Social Network Kit, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2019-07-29.

How severe is CVE-2019-12743?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Humhub Social Network Kit

CVE-2019-12743

HumHub Social Network Kit Enterprise v1.3.13 allows remote attackers to find the user accounts existing on any Social Network Kits (including self-hosted ones) by brute-forcing the username after the /u/ initial URI substring, aka Response Discrepancy Information Exposure.

Published 2019-07-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.015 (73.3th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Humhub Social Network Kit — versions 1.3.13

Weakness classification (CWE)

CWE-203 — Observable Discrepancy

References

humhub.org/en/news (Product, Release Notes)
github.com/chanpu9/CVE/blob/master/2019-12743 (Third Party Advisory)

Frequently asked questions

What is CVE-2019-12743?: CVE-2019-12743 is a medium-severity vulnerability in Humhub Social Network Kit, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2019-07-29.
How severe is CVE-2019-12743?: Medium severity. CVSS v3 base score is 5.3 out of 10.