Auth bypass in Bookwyrm-Social Bookwyrm
CVE-2026-86113
BookWyrm through 0.9.1 contains an authorization bypass vulnerability in the edit_readthrough function that allows authenticated users to modify other users' reading records. Attackers can exploit sequential ReadThrough IDs to overwrite arbitrary users' start dates, finish dates, progress, and progress mode, affecting reading statistics and exported data.
Vulnerability class: IDOR (Insecure Direct Object Reference)
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:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (35.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.2% 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
Weakness classification (CWE)
References
- github.com/bookwyrm-social/bookwyrm (product)
- edit_readthrough: no ownership check (technical-description)
- Researcher write-up: finding 3 (technical-description)
- VulnCheck Advisory: BookWyrm through 0.9.1 Insecure Direct Object Reference in edit-readthrough Allows Tampering with Other Users' Reading Records (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86113?
- CVE-2026-86113 is a medium-severity vulnerability in Bookwyrm-Social Bookwyrm, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-09-05.
- How severe is CVE-2026-86113?
- Medium severity. CVSS v3 base score is 6.5 out of 10.