CVE intelligence and bounded remediation

CVE-2026-25154 — Localsend Localsend security vulnerability

Medium CVSS 6.1

LocalSend is a free, open-source app that allows users to share files and messages with nearby devices over their local network without needing an internet connection. In versions up to and including 1.17.0, when a user initiates a "Share via Link" session, the LocalSend application starts a local HTTP server to host the selected files. The client-side logic for this web interface is contained in `app/assets/web/main.js`. Note that at [0], the `handleFilesDisplay` function constructs the HTML for the file list by iterating over the files received from the server. Commit 8f3cec85aa29b2b13fed9b2f8e499e1ac9b0504c contains a patch.

Severity
Medium
CVSS
6.1 (3.1)
Published
2026-01-30
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • localsend / localsend

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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