Auth bypass in Bookwyrm-Social Bookwyrm
CVE-2026-86112
BookWyrm through 0.9.1 fails to validate user visibility permissions in the Favorite and Unfavorite views, allowing authenticated attackers to favorite or unfavorite followers-only and direct statuses they cannot access. Attackers can POST to the favorite endpoint with a status ID to create unauthorized interactions, trigger ActivityPub broadcasts, and enumerate private status IDs through response differentiation.
Vulnerability class: IDOR (Insecure Direct Object Reference)
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86112?
- CVE-2026-86112 is a medium-severity vulnerability in Bookwyrm-Social Bookwyrm, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2026-09-05.
- How severe is CVE-2026-86112?
- Medium severity. CVSS v3 base score is 5.4 out of 10.