CVE-2026-57439 Details
Description
CyberChef is a web app for encryption, encoding, compression, and data analysis. Prior to 11.2.0, the Series Chart operation accepts __proto__ as a key while parsing user-supplied CSV, allowing prototype pollution that can be chained with operations such as Parse UDP to inject malicious JavaScript into HTML output. This issue is fixed in version 11.2.0.
A prototype pollution vulnerability has been identified in the CyberChef web application, specifically within the Series Chart operation, prior to version 11.2.0. This vulnerability allows for the injection of malicious JavaScript into the HTML output by exploiting the operation's CSV parsing capabilities. The issue arises because the Series Chart operation accepts '__proto__' as a key, which can be used to manipulate the prototype of objects. This polluted prototype can then be exploited by chaining it with other operations, such as Parse UDP, to execute arbitrary JavaScript. The vulnerability is made possible because the objToTable function, which renders data as an HTML table, does not properly escape inherited properties, creating an opportunity for cross-site scripting (XSS) attacks.
Users are advised to upgrade to CyberChef version 11.2.0 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 8, 2026CISA-ADP
Assessed Jul 8, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/gchq/CyberChef/commit/85db3be5d0096859b810f0e8d3e151d5dc9b948f | [email protected] | Source CodeVendor |
| https://github.com/gchq/CyberChef/issues/2568 | [email protected] | ExploitIssue TrackingTechnical DescriptionVendor |
| https://github.com/gchq/CyberChef/pull/2569 | [email protected] | Issue TrackingVendor |
| https://github.com/gchq/CyberChef/releases/tag/v11.2.0 | [email protected] | Release NotesVendor |
| https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1321 | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') | [email protected] |
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| GCHQ CyberChef | < 11.2.0 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 8, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2026 | New CVE Received | [email protected] |