Auth bypass in Stoatchat
CVE-2026-73059
stoatchat before 0.15.0 contains a permission bypass vulnerability in the message_fetch route that checks only ViewChannel permission instead of requiring ReadMessageHistory. Attackers with ViewChannel access but ReadMessageHistory denied can retrieve individual message content by ID, bypassing the intended history restriction enforced by bulk read routes.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (29.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Stoatchat — versions 0, 0.15.0
Weakness classification (CWE)
References
- github.com/stoatchat/stoatchat/security/advisories/GHSA-8qp4-h9xf-2vqr (vendor-advisory)
- www.vulncheck.com/advisories/stoatchat-before-permission-bypass-via-message-fet… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73059?
- CVE-2026-73059 is a medium-severity vulnerability in Stoatchat, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-08-16.
- How severe is CVE-2026-73059?
- Medium severity. CVSS v3 base score is 6.5 out of 10.