Auth bypass in Yaoapp Yao
CVE-2026-91774
Yao through v1.0.0-rc22 authenticates but fails to authorize the GET /user/teams/:id endpoint, allowing any logged-in user to read full team records. Attackers can supply a known team identifier to retrieve sensitive team data including name, description, owner information, and settings without membership verification.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (27.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% 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: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/YaoApp/yao/issues/1553 (issue-tracking)
- github.com/YaoApp/yao/blob/v1.0.0-rc22/openapi/user/team.go (technical-description)
- github.com/YaoApp/yao/blob/v1.0.0-rc22/openapi/oauth/providers/user/team.go (technical-description)
- github.com/YaoApp/yao (product)
- www.vulncheck.com/advisories/yao-through-1.0.0-rc22-missing-authorization-via-o… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91774?
- CVE-2026-91774 is a medium-severity vulnerability in Yaoapp Yao, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-15.
- How severe is CVE-2026-91774?
- Medium severity. CVSS v3 base score is 4.3 out of 10.