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.

CVSS v3 5.4 MEDIUM

5.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/bookwyrm-social/bookwyrm
https://github.com/bookwyrm-social/bookwyrm/blob/v0.9.1/bookwyrm/views/interaction.py
https://github.com/geo-chen/oss/blob/main/bookwyrm.md#finding-2-authenticated-idor-in-favoriteunfavorite-allows-interaction-with-private-statuses
https://www.vulncheck.com/advisories/bookwyrm-through-0.9.1-missing-authorization-on-the-favorite-and-unfavorite-endpoints

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-05 10:16

Updated : 2026-09-10 16:18

NVD link : CVE-2026-86112

Mitre link : CVE-2026-86112

CVE.ORG link : CVE-2026-86112

JSON object : View

Products Affected

No product.

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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