Executive brief
BookWyrm is a decentralized social platform for tracking and sharing book reading activity. A vulnerability in versions through 0.9.1 allows logged-in users to modify other users' reading records by bypassing authorization checks, potentially corrupting reading history, statistics, and exported data for other accounts.
Technical details
The vulnerability is an authorization bypass in the edit_readthrough function that fails to properly verify that an authenticated user owns the reading record being modified. An attacker can exploit predictable, sequential ReadThrough object IDs to craft requests that modify other users' reading records—changing start dates, finish dates, reading progress, and progress mode. No special privileges are required beyond basic authentication, and the attack is straightforward to execute via direct HTTP requests. The vulnerability affects all versions through 0.9.1; patches are available in later releases.
Affected products
- BookWyrm BookWyrm through 0.9.1
Timeline
- 2026-09-05: disclosed