CVE-2021-3768 json
Cross-site Scripting (XSS) - Stored in bookstackapp/bookstack
published 2021-09-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27037
- cvss
- 5.4
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 47%
- public exploits
- 0
- none known
Summary
bookstack is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Patch / fix
- bookstackapp bookstackapp/bookstack 21.08.2
Exploit prediction
0.58% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- huntr.dev https://huntr.dev/bounties/64a0229f-ff5e-4c64-b83e-9bfc0698a78e referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 5.4 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Affected products
- bookstackapp bookstackapp/bookstack
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/bookstackapp/bookstack/commit/5e6092aaf8fd420202016038286554860bf8ea64
patch, third-party-advisory
-
huntr.dev
/bounties/64a0229f-ff5e-4c64-b83e-9bfc0698a78e
exploit, issue-tracking, patch, third-party-advisory
Sources
- CVE List CVE-2021-3768
- NVD CVE-2021-3768
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.