CVE-2026-45243

Name: CVE-2026-45243
Creator: NVD / NIST
Published: 2026-05-18T19:16:28.387+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.19%

Last modified Jun 17, 2026

CVE-2026-45243 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS 4.0

5.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.19%

9.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Steipete	Summarize	< 0.15.1

References

https://github.com/steipete/summarize/commit/357544063af535bd574752622f9eb94be33ee5fdPatch
https://github.com/steipete/summarize/pull/222Exploit, Issue Tracking, Patch
https://github.com/steipete/summarize/releases/tag/v0.15.2Release Notes
https://www.vulncheck.com/advisories/summarize-browser-extension-missing-authorization-via-content-scriptThird Party Advisory

Timeline

Published: May 18, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-45243?

How severe is CVE-2026-45243?

CVE-2026-45243 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-45243?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-45243?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST