CVE-2026-42615

high

Description

GCHQ CyberChef before 11.0.0 allows XSS via Show Base64 offsets, as demonstrated by the /#recipe=Show_Base64_offsets('%3Cscript substring.

References

https://github.com/gchq/CyberChef/pull/2346

https://github.com/gchq/CyberChef/issues/2344

https://github.com/gchq/CyberChef/compare/v10.24.0...v11.0.0

https://github.com/gchq/CyberChef/commit/9641ae07f92e9af50f10e978385465b2f4a36c4d

Details

Source: Mitre, NVD

Published: 2026-04-29

Updated: 2026-04-29

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.2

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Severity: High