CVE-2026-86644
star7th showdoc API Page Save Endpoint editormd.js cross site scripting
Description
A vulnerability was determined in star7th showdoc up to 3.9.1. This vulnerability affects unknown code of the file web_src/public/editor.md/editormd.js of the component API Page Save Endpoint. Executing a manipulation can lead to cross site scripting. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 3.9.2 is able to resolve this issue. This patch is called a8ea1520850b4242f395247f72e87e597506cef0. Upgrading the affected component is recommended. The vendor confirms: "The fix [...] sets Mermaid `securityLevel` to `strict`, disables `htmlLabels`, and sanitizes rendered SVG with DOMPurify."
INFO
Published Date :
Sept. 8, 2026, 2:17 p.m.
Last Modified :
Sept. 8, 2026, 2:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-86644
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Upgrade to version 3.9.2.
- Apply patch a8ea1520850b4242f395247f72e87e597506cef0.
- Configure Mermaid securityLevel to strict.
- Sanitize rendered SVG with DOMPurify.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-86644.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-86644 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-86644
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-86644 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-86644 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 08, 2026
Action Type Old Value New Value Added Description A vulnerability was determined in star7th showdoc up to 3.9.1. This vulnerability affects unknown code of the file web_src/public/editor.md/editormd.js of the component API Page Save Endpoint. Executing a manipulation can lead to cross site scripting. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 3.9.2 is able to resolve this issue. This patch is called a8ea1520850b4242f395247f72e87e597506cef0. Upgrading the affected component is recommended. The vendor confirms: "The fix [...] sets Mermaid `securityLevel` to `strict`, disables `htmlLabels`, and sanitizes rendered SVG with DOMPurify." Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N Added CVSS V2 (AV:N/AC:L/Au:S/C:N/I:P/A:N) Added CWE CWE-79 Added CWE CWE-94 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/86xxx/CVE-2026-86644.json">CVE-2026-86644</a> Added Reference https://gist.github.com/saDL0w/36a72a076e9ab24408a3d27582e778b2 Added Reference https://github.com/star7th/showdoc/ Added Reference https://github.com/star7th/showdoc/commit/a8ea1520850b4242f395247f72e87e597506cef0 Added Reference https://github.com/star7th/showdoc/releases/tag/v3.9.2 Added Reference https://vuldb.com/cve/CVE-2026-86644 Added Reference https://vuldb.com/submit/906282 Added Reference https://vuldb.com/vuln/399755 Added Reference https://vuldb.com/vuln/399755/cti