CVE-2026-42615CWE-79

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

High · published April 29, 2026

CVSS v3.1
7.2
EPSS
0%
Percentile
29.3
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
7.2 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00366 · 29.3th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-04-29T02:55Z
EPSS history
Timeline
  • 29 APR 02:55Z
    GCHQ CyberChef before 11.0.0 allows XSS via Show Base64 offsets, as demonstrated by the /#recipe=Show_Base64_offsets('%3Cscript substring
    cvelistv5