Get a Demo

Let's Patch It!

Book a short call with one our specialists, we'll walk you through how Endor Patches work, and ask you a few questions about your environment (like your primary programming languages and repository management). We'll also send you an email right after you fill out the form, feel free to reply with any questions you have in advance!

CVE

CVE-2026-66824

Stored Cross-Site Scripting via Unsafe Capture Tree JSON Embedding
Back to all
CVE

CVE-2026-66824

Stored Cross-Site Scripting via Unsafe Capture Tree JSON Embedding

A stored cross-site scripting vulnerability existed in the capture tree visualization page. The application embedded the serialized capture tree directly into an inline JavaScript block using the Jinja safe filter.

Because the tree data can contain values derived from captured and potentially attacker-controlled web content, a specially crafted value could prematurely terminate the surrounding <script> element and inject arbitrary HTML or JavaScript. The malicious code would execute in the browser of a user viewing the affected capture tree.

Successful exploitation could allow an attacker to perform actions using the victim’s authenticated session, access information available to the victim, or modify application data within the permissions of the affected user.

The patch removes the JSON data from the HTML document and retrieves it through a dedicated API endpoint. The client then processes the response using response.json(), preventing capture data from being interpreted as executable content within the original page’s HTML or JavaScript context.

Package Versions Affected

Package Version
patch Availability
No items found.

Automatically patch vulnerabilities without upgrading

Fix Without Upgrading
Detect compatible fix
Apply safe remediation
Fix with a single pull request

CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.2
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:N/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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/Lookyloo/lookyloo/, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66824.json, https://nvd.nist.gov/vuln/detail/CVE-2026-66824, https://github.com/Lookyloo/lookyloo/commit/395187b57322ab311363ccc290c010b180389009

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.00277%
EPSS Percentile
0.20245%
Introduced Version
0
Fix Available
395187b57322ab311363ccc290c010b180389009

Fix Critical Vulnerabilities Instantly

Secure your app without upgrading.
Fix Without Upgrading