CVE-2026-45243 Summarize < 0.15.1 Browser Extension Missing Authorization via Content Script

What is CVE-2026-45243?

CVE-2026-45243 is a medium-severity missing authorization vulnerability in steipete summarize, published on 18 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Summarize prior to 0.15.1 contains a missing authorization vulnerability in the content script window.postMessage bridge that allows malicious pages to perform unauthorized operations on automation artifacts. Attackers can simulate runtime messages with spoofed sender identifiers to list, read, create, overwrite, or delete automation artifacts scoped to the affected tab without proper authorization checks.

Weakness: CWE-862

Which versions are affected by CVE-2026-45243?

2 open source packages ship an affected version, including @steipete/summarize. It affects 1 product.

Products include Steipete Summarize.

How do I fix CVE-2026-45243?

Upgrade @steipete/summarize to 0.15.0 or later.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-45243 being exploited?

There is no known exploitation of CVE-2026-45243 in the wild and no public exploit code.

Other vulnerabilities in steipete summarize

• CVE-2026-45242 Summarize < 0.15.1 Path Traversal via slidesDir Parameter High 7.1
• CVE-2026-45246 Summarize < 0.15.1 Insecure File Permissions Information Disclosure Medium 6.8
• CVE-2026-45245 Summarize < 0.15.1 Unauthorized Daemon Request via Untrusted Events Medium 4.6
• CVE-2026-45244 Summarize < 0.15.1 Unapproved Browser Automation Execution Low 2.1

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5624-2pmv-jx46.