Auth bypass in Stoatchat
CVE-2026-74869
stoatchat before 0.15.0 contains a missing authorization vulnerability in the Subscribe message handler that allows authenticated attackers to enumerate members and monitor profile updates of private servers without membership. Attackers can subscribe to any server's member-update topic by sending a Subscribe message with an arbitrary server ID, receiving live UserUpdate events including display names, avatars, and status changes for members they should not have access to.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (26.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Stoatchat — versions 0, 0.15.0
Weakness classification (CWE)
References
- github.com/stoatchat/stoatchat/security/advisories/GHSA-jj3j-9qr7-jgfc (vendor-advisory)
- www.vulncheck.com/advisories/stoatchat-before-missing-authorization-via-subscri… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-74869?
- CVE-2026-74869 is a high-severity vulnerability in Stoatchat, classified under Missing Authorization. CVSS score: 7.7/10. Published 2026-08-17.
- How severe is CVE-2026-74869?
- High severity. CVSS v3 base score is 7.7 out of 10.