Is CVE-2026-40186 actively exploited?

No active exploitation of CVE-2026-40186 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40186 be exploited remotely?

Yes. CVE-2026-40186 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40186?

CVE-2026-40186 has a CVSS score of 6.1 (MEDIUM).

HOME VULNERABILITIESCVE-2026-40186

MEDIUM

CVE-2026-40186

CWE-79Published: April 15, 2026· Updated: Apr 17, 2026

6.1

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:8.1th

Official Description

ApostropheCMS is an open-source Node.js content management system. A regression introduced in commit 49d0bb7, included in versions 2.17.1 of the ApostropheCMS-maintained sanitize-html package bypasses allowedTags enforcement for text inside nonTextTagsArray elements (textarea and option). ApostropheCMS version 4.28.0 is affected through its dependency on the vulnerable sanitize-html version. The code at packages/sanitize-html/index.js:569-573 incorrectly assumes that htmlparser2 does not decode entities inside these elements and skips escaping, but htmlparser2 10.x does decode entities before passing text to the ontext callback. As a result, entity-encoded HTML is decoded by the parser and then written directly to the output as literal HTML characters, completely bypassing the allowedTags filter. An attacker can inject arbitrary tags including XSS payloads through any allowed option or textarea element using entity encoding. This affects non-default configurations where option or textarea are included in allowedTags, which is common in form builders and CMS platforms. This issue has been fixed in version 2.17.2 of sanitize-html and 4.29.0 of ApostropheCMS.

NVD Source

Technical Analysis

CVE-2026-40186 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.