CVE-2026-57439

CyberChef: Prototype pollution in Series Chart operation

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.

Affected

gchq · CyberChef

CVSS v3.1 GITHUB

5.0 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

0.24% chance of exploitation in the next 30 days, 15th percentile

Published

2026-07-08

Proof-of-concept exploits (1)

• advisories/GHSA-fx6f-382r-j72c

References

• CVE Record
• NVD entry