mo has a XSS via inline SVG script tags in Markdown rendering
What to do
Vendor fix available. Upgrade each affected package to the fixed version on its release line (github.com/k1LoW/mo 0.18.5), redeploy, then verify what is actually installed.
This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.
Affected packages
- Affected
- <= 0.18.4
- Fixed in
- 0.18.5
Sources
- GitHub Advisory Database and maintainer security advisories on GitHub
GitHub-reviewed advisory GHSA-vccx-p757-pv6h lists affected ranges: Go github.com/k1LoW/mo >=0 <=0.18.4
VerifiedObserved Structured GitHub Advisory Database record (type=reviewed) from the GitHub REST API.
Severity and exploitation
- Exploitation
- No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
- CVSS 4.0
- 2.3 · CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source
- EPSS
- No dated EPSS signal available.
Source description
As published by the source; long descriptions are shortened.
Summary When rendering Markdown files containing inline SVG elements with <script tags, the embedded JavaScript is executed in the browser. This is due to rehype-raw passing raw HTML (including SVG) through to the DOM without sanitization. PoC Embedding the above in a Markdown file opened with mo causes the script to execute. Impact Arbitrary JavaScript execution in the context of the mo application when a user opens a malicious Markdown file. This could lead to data exfiltration of other opened Markdown file contents. Remediation Fixed by adding rehype-sanitize to the Markdown rendering pipeline, which strips dangerous elements such as <script while preserving safe HTML.
Dates and revisions
- Published by the source
- Last modified by the source
- Source last checked
- Revision 1 · created ·
Published from ghsa record GHSA-vccx-p757-pv6h
Agent brief
Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.
# Patch Next advisory brief: GHSA-vccx-p757-pv6h Advisory: mo has a XSS via inline SVG script tags in Markdown rendering IDs: GHSA-vccx-p757-pv6h Record: https://patchnext.com/advisories/ghsa-vccx-p757-pv6h (revision 1, source checked 26 Oct 2026, 15:18 UTC) Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected. Severity: Low (CVSS 2.3) Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV. Vendor response: Vendor fix available; fixed versions by package: github.com/k1LoW/mo 0.18.5. A vendor fix does not mean a deployment is fixed. ## Affected components - Go github.com/k1LoW/mo: affected <= 0.18.4; fixed in 0.18.5 ## Suggested inspection (read-only) - Go github.com/k1LoW/mo: check the installed version with your package manager. ## Supported action Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version. ## Required regression checks - Run the test suite and a production build. - Exercise the features that depend on github.com/k1LoW/mo. - Repeat the inspection and confirm that only fixed versions remain installed. ## Rollback considerations - Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward. ## Unresolved questions - Which deployments run an affected version? - Exploitation status can change. Check again before lowering the priority. - Mark the work resolved only after the fixed version is verified in production. ## Sources - Verified: https://github.com/advisories/GHSA-vccx-p757-pv6h (GitHub-reviewed advisory GHSA-vccx-p757-pv6h lists affected ranges: Go github.com/k1LoW/mo >=0 <=0.18.4) Commands are suggestions: review each one before running it.
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