XSS in Apostrophecms Apostrophe
CVE-2026-112958
ApostropheCMS is an open-source Node.js content management system. Prior to 4.34.0, a project-defined free-form widget style field can carry an editor-controlled quote into an inline style attribute because the wrapper serializer does not apply HTML-attribute encoding. The quote can terminate the style attribute and inject executable attributes when published content, or an affected draft viewed by a higher-privileged user, is rendered. This issue is fixed in version 4.34.0.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Apostrophecms Apostrophe — versions < 4.34.0
Weakness classification (CWE)
References
- github.com/apostrophecms/apostrophe/security/advisories/GHSA-7jg5-frgc-c67w
- github.com/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c32dccd7e505ad5dd…
- github.com/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029b8ce7668634265cf…
- github.com/apostrophecms/apostrophe/releases/tag/apostrophe@4.34.0
Frequently asked questions
- What is CVE-2026-112958?
- CVE-2026-112958 is a medium-severity vulnerability in Apostrophecms Apostrophe, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-10-20.
- How severe is CVE-2026-112958?
- Medium severity. CVSS v3 base score is 5.4 out of 10.