CVE-2026-57439 PUBLISHED

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.

• https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c
• https://github.com/gchq/CyberChef/issues/2568
• https://github.com/gchq/CyberChef/pull/2569
• https://github.com/gchq/CyberChef/commit/85db3be5d0096859b810f0e8d3e151d5dc9b948f
• https://github.com/gchq/CyberChef/releases/tag/v11.2.0

• CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE
• CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') CWE