CVE-2021-4296 json
w3c Unicorn ValidatorNuMessage.java ValidatorNuMessage cross site scripting
published 2022-12-29 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34132
- cvss
- 3.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
A vulnerability, which was classified as problematic, has been found in w3c Unicorn. This issue affects the function ValidatorNuMessage of the file src/org/w3c/unicorn/response/impl/ValidatorNuMessage.java. The manipulation of the argument message leads to cross site scripting. The attack may be initiated remotely. The name of the patch is 51f75c31f7fc33859a9a571311c67ae4e95d9c68. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-217019.
Patch / fix
Exploit prediction
0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N |
| CNA | 3.0 | 3.5 | CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected products
- w3c Unicorn
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/w3c/Unicorn/pull/212
issue-tracking, third-party-advisory
-
github.com
/w3c/Unicorn/commit/51f75c31f7fc33859a9a571311c67ae4e95d9c68
patch, third-party-advisory
-
vuldb.com
/?id.217019
vdb-entry, technical-description, third-party-advisory
-
vuldb.com
/?ctiid.217019
signature, permissions-required, third-party-advisory
Sources
- CVE List CVE-2021-4296
- NVD CVE-2021-4296
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.