CVE-2021-4026 json
Improper Access Control in bookstackapp/bookstack
published 2021-11-30 4 y ago modified 2026-06-17 4 mo ago also GHSA-jm6p-wfjg-xm7x , EUVD-2021-2546
- cvss
- 6.5
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 60%
- public exploits
- 0
- none known
Summary
bookstack is vulnerable to Improper Access Control
Patch / fix
- packagist ssddanbrown/bookstack 21.11.2
- bookstackapp bookstackapp/bookstack 21.11.2
Exploit prediction
0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- huntr.dev https://huntr.dev/bounties/c6dfa80d-43e6-4b49-95af-cc031bb66b1d referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 6.5 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:P/I:N/A:N |
| GitHub | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | ssddanbrown/bookstack | <21.11.2 |
21.11.2 |
Affected products
- bookstackapp bookstackapp/bookstack
Classification
References
-
github.com
/bookstackapp/bookstack/commit/b4fa82e3298a15443ca40bff205b7a16a1031d92
web, patch, third-party-advisory
-
huntr.dev
/bounties/c6dfa80d-43e6-4b49-95af-cc031bb66b1d
web, exploit, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-4026
advisory
-
github.com
/BookStackApp/BookStack/releases/tag/v21.11.2
web
-
github.com
/bookstackapp/bookstack
web
Sources
- CVE List CVE-2021-4026
- GitHub Advisory GHSA-jm6p-wfjg-xm7x
- NVD CVE-2021-4026
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.