# CVE-2026-45243: steipete Summarize missing authorization in content script bridge

Source: https://junglewise.ai/threats/cve-2026-45243-steipete-summarize-missing-authorization-in-content-script-bridge  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-18. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-45243 · Severity: medium · CVSS 6.1 · Published 2026-05-18

Summarize is a Chrome extension that summarizes web content and manages automation artifacts. A missing authorization vulnerability in the extension's content script allowed malicious webpages to read, create, or delete automation artifacts stored by the extension without proper permission checks. An attacker could craft a malicious webpage to intercept and manipulate automation data belonging to users visiting that page.

Technologies: [@steipete/summarize (npm)](https://junglewise.ai/threats/technologies/steipete-summarize), [Steipete Summarize](https://junglewise.ai/threats/technologies/summarize). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Steipete](https://junglewise.ai/threats/vendors/steipete).

## Quick answers

**Is CVE-2026-45243 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45243 being exploited in the wild.

**How severe is CVE-2026-45243?** Medium severity, with a CVSS score of 6.1, published 18 May 2026.

**Which products and versions are affected?** @steipete/summarize (npm) < 0.15.0, SEMVER:introduced=0,fixed=0.15.0; Steipete Summarize < 0.15.0, prior to 0.15.0, prior to 0.15.1.

**Is there a fix for CVE-2026-45243?** Yes. @steipete/summarize (npm): upgrade to 0.15.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45243 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-45243?** Check whether you run @steipete/summarize (npm) or Steipete Summarize at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @steipete/summarize (npm): upgrade to 0.15.0 or later

  ```sh
  npm install @steipete/summarize@0.15.0
  ```


## Technical details

The vulnerability is a missing authorization check (CWE-862) in the content script's window.postMessage bridge used for automation artifact management. The vulnerable code in the all-pages automation content script accepted message events from untrusted page scripts and forwarded them directly to the background worker as automation:artifacts messages without verifying that the request originated from trusted extension code. An attacker could craft JavaScript on a malicious webpage to send forged postMessage events with action and payload parameters to list, read, create, overwrite, or delete tab-scoped automation artifacts. The only scope check performed was the sender's tab ID, which is controlled by the attacker's page context. The fix (released in v0.15.0) removes the page-visible postMessage bridge entirely, moves artifact operations to the extension's user-script messaging channel (chrome.runtime.sendMessage), and requires an explicit extension-origin arm/disarm handshake before artifact operations are accepted by the background worker.

## Affected products

- steipete Summarize prior to 0.15.0

## Identifiers

- CVE-2026-45243
- GHSA-5624-2pmv-jx46

## Timeline

- 2026-05-18: disclosed: Vulnerability published
- 2026-05-15: patched: Fix released in version 0.15.0
- 2026-05-29: advisory: GitHub security advisory reviewed

## References

- [https://github.com/steipete/summarize/pull/222](https://github.com/steipete/summarize/pull/222)
- [https://github.com/steipete/summarize/commit/357544063af535bd574752622f9eb94be33ee5fd](https://github.com/steipete/summarize/commit/357544063af535bd574752622f9eb94be33ee5fd)
- [https://github.com/steipete/summarize](https://github.com/steipete/summarize)
- [https://github.com/steipete/summarize/releases/tag/v0.15.1](https://github.com/steipete/summarize/releases/tag/v0.15.1)
- [https://github.com/steipete/summarize/releases/tag/v0.15.2](https://github.com/steipete/summarize/releases/tag/v0.15.2)
- [https://www.vulncheck.com/advisories/summarize-browser-extension-missing-authorization-via-content-script](https://www.vulncheck.com/advisories/summarize-browser-extension-missing-authorization-via-content-script)

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