CVE-2026-86112 json
BookWyrm through 0.9.1 Missing Authorization on the Favorite and Unfavorite Endpoints
published 2026-09-05 2 mo ago modified 2026-09-24 45 d ago also EUVD-2026-71944
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 59 d ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- bookwyrm-social bookwyrm
Classification
- Weakness
-
- CWE-639 Authorization Bypass Through User-Controlled Key
References
-
github.com
/geo-chen/oss/blob/main/bookwyrm.md#finding-2-authenticated-idor-in-favoriteunfavorite-allows-interaction-with
technical-description
-
github.com
/bookwyrm-social/bookwyrm/blob/v0.9.1/bookwyrm/views/interaction.py
technical-description
-
github.com
/bookwyrm-social/bookwyrm
product
-
vulncheck.com
/advisories/bookwyrm-through-0.9.1-missing-authorization-on-the-favorite-and-unfavorite-endpoints
third-party-advisory
Sources
- CVE List CVE-2026-86112
- NVD CVE-2026-86112
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.