CVE-2026-112951 json
ApostropheCMS: Color field validation bypass allows stored XSS via HTML appended after rgb()/hsl() prefix
published 20d ago modified 19d ago also EUVD-2026-105154 , GHSA-vmgj-9cwm-cf3h
- 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
ApostropheCMS is an open-source Node.js content management system. Prior to 4.34.0, the color field accepts trailing content after a valid rgb() or hsl() prefix because its TinyColor validation does not require the entire value to match a color. An authenticated user with edit rights can store arbitrary HTML after a valid color prefix. When the stored value is rendered, the payload executes, resulting in stored XSS. This issue is fixed in version 4.34.0.
Patch / fix
- npm apostrophe 4.34.0
- apostrophecms apostrophecms 4.34.0
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 20d ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-vmgj-9cwm-cf3h referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | apostrophe | <4.34.0 |
4.34.0 |
Affected products
- apostrophecms apostrophe
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c32dccd7e505ad5ddf498
web
-
github.com
/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029b8ce7668634265cfe5ea
web
-
github.com
/apostrophecms/apostrophe/security/advisories/GHSA-vmgj-9cwm-cf3h
exploit, web
-
github.com
/apostrophecms/apostrophe/releases/tag/apostrophe@4.34.0
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-112951
advisory
-
github.com
/apostrophecms/apostrophe
package
Sources
- CVE List CVE-2026-112951
- GitHub Advisory GHSA-vmgj-9cwm-cf3h
- NVD CVE-2026-112951
Fencer Intel 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.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.