Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Unratedamended

HTML Injection in preact

GHSA-cg48-9hh2-x6mx

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (preact 10.0.0-beta.1), 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.

Add to your agent

Affected packages

  • npm preact

    Affected
    >= 10.0.0-alpha.0, <= 10.0.0-beta.0
    Fixed in
    10.0.0-beta.1

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
not scored
EPSS
No dated EPSS signal available.
Source description

As published by the source; long descriptions are shortened.

Versions of preact 10.x on prerelease tags alpha and beta prior to 10.0.0-beta.1 are vulnerable to HTML Injection. Due to insufficient input validation the package allows attackers to inject JavaScript objects as virtual-dom nodes, which may lead to Cross-Site Scripting. This requires user input parsed with JSON.parse() to be passed directly into JSX without sanitization. Recommendation Upgrade to version 10.0.0-beta.1.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 2 · amended ·

    Amended from ghsa record GHSA-cg48-9hh2-x6mx

  2. Revision 1 · created ·

    Published from osv record GHSA-cg48-9hh2-x6mx

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-cg48-9hh2-x6mx

Advisory: HTML Injection in preact
IDs: GHSA-cg48-9hh2-x6mx
Record: https://patchnext.com/advisories/ghsa-cg48-9hh2-x6mx (revision 2, source checked 26 Oct 2026, 12:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: preact 10.0.0-beta.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm preact: affected >= 10.0.0-alpha.0, <= 10.0.0-beta.0; fixed in 10.0.0-beta.1

## Suggested inspection (read-only)
- `npm ls preact --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 preact.
- 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://osv.dev/vulnerability/GHSA-cg48-9hh2-x6mx (OSV record GHSA-cg48-9hh2-x6mx lists affected ranges: npm preact >=10.0.0-alpha.0 <10.0.0-beta.1 (fixed))
- Verified: https://github.com/advisories/GHSA-cg48-9hh2-x6mx (GitHub-reviewed advisory GHSA-cg48-9hh2-x6mx lists affected ranges: npm preact >=10.0.0-alpha.0 <=10.0.0-beta.0)

Commands are suggestions: review each one before running it.

Loading voting…