CVE-2026-57439

EUVD-2026-42294
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.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
GitHub_MCNA
5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
gchqcyberchef
𝑥
< 11.2.0
CNA
Common Weakness Enumeration
References
https://github.com/gchq/CyberChef/commit/85db3be5d0096859b810f0e8d3e151d5dc9b948f
https://github.com/gchq/CyberChef/issues/2568
https://github.com/gchq/CyberChef/pull/2569
https://github.com/gchq/CyberChef/releases/tag/v11.2.0
https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c
https://github.com/gchq/CyberChef/security/advisories/GHSA-fx6f-382r-j72c