CVE-2026-45243Public exploitNetwork attack vector

Unauthorized artifact access via unguarded message bridge

Published May 18, 2026 · Updated May 18, 2026

Missing authorization in Summarize before 0.15.1 allows remote attackers to read or alter tab-scoped automation artifacts via a malicious page. The all-pages content script accepted page-controlled window.postMessage actions and payloads, then forwarded them to a background worker that trusted the sender tab without requiring an armed automation run. A user must visit a malicious page with the browser extension installed; exposure is limited to that tab's artifacts, including their creation, overwrite, and deletion.

CVSS severity5.3
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authorization in Summarize before 0.15.1 allows remote attackers to read or alter tab-scoped automation artifacts via a malicious page. The all-pages content script accepted page-controlled window.postMessage actions and payloads, then forwarded them to a background worker that trusted the sender tab without requiring an armed automation run. A user must visit a malicious page with the browser extension installed; exposure is limited to that tab's artifacts, including their creation, overwrite, and deletion.

The record

CVE
CVE-2026-45243
Published
May 18, 2026
Updated
May 18, 2026
Vendor
steipete
Product
Summarize
Classifications
CWE-862, T1005, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 18, 2026CVE publishedPublication date reported by the CVE source.
  2. May 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.15.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

steipete · Summarizeversion=0 <0.15.1

Published CVSS scores

6.1VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1005Data from Local System
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo