CVE-2026-23630Public exploitNetwork attack vector

Stored XSS via unsanitized Mermaid DOM insertion

Published Jan 21, 2026 · Updated Jan 21, 2026

Stored XSS in Docmost 0.3.0 through 0.23.2 allows remote authenticated users to execute JavaScript when another user views a crafted page. The Mermaid view passes attacker-controlled diagrams to mermaid.render() and inserts its unsanitized SVG/HTML result with dangerouslySetInnerHTML. Page-editing access is required to store a diagram, and viewing the page runs the payload in the viewer's Docmost origin.

CVSS severity6.3
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Docmost 0.3.0 through 0.23.2 allows remote authenticated users to execute JavaScript when another user views a crafted page. The Mermaid view passes attacker-controlled diagrams to mermaid.render() and inserts its unsanitized SVG/HTML result with dangerouslySetInnerHTML. Page-editing access is required to store a diagram, and viewing the page runs the payload in the viewer's Docmost origin.

The record

CVE
CVE-2026-23630
Published
Jan 21, 2026
Updated
Jan 21, 2026
Vendor
Docmost
Product
Docmost
Classifications
CWE-116, CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.3.0, < 0.24.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Docmost · Docmostversion=>= 0.3.0, < 0.24.0

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

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