CVE-2026-86644star7th showdoc API Page Save Endpoint editormd.js cross site scripting
- 5.1MediumCVSS base score
- 0.36%Exploitation in 30 daysEPSS · top 69% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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."
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By VulDB
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium5.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | Low3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C |
| VulDBCNA (assigner) | 3.0 | Low3.5 | CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C |
| VulDBCNA (assigner) | 2.0 | Medium4.0 | AV:N/AC:L/Au:S/C:N/I:P/A:N/E:POC/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Low2.0 | CVSS:4.0/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 |
- EPSS (exploitation in 30 days)
- 0.36% · top 69% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.1.
Affected products
References
References8
- VDB-399755 | star7th showdoc API Page Save Endpoint editormd.js cross site scripting (opens in a new tab)vdb-entry
- VDB-399755 | CTI Indicators (IOB, IOC, TTP, IOA) (opens in a new tab)signaturepermissions-required
- CVE-2026-86644 | CVE Analysis and Report (opens in a new tab)third-party-advisory
- Submit #906282 | star7th ShowDoc 3.7.1 - 3.9.1 Cross Site Scripting (opens in a new tab)third-party-advisory
- https://gist.github.com/saDL0w/36a72a076e9ab24408a3d27582e778b2 (opens in a new tab)exploit
- https://github.com/star7th/showdoc/commit/a8ea1520850b4242f395247f72e87e597506cef0 (opens in a new tab)patch
- https://github.com/star7th/showdoc/releases/tag/v3.9.2 (opens in a new tab)patch
- https://github.com/star7th/showdoc/ (opens in a new tab)product
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-72760 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-86644)Record last updated .