PT-2026-35866 · Gchq · Cyberchef

Gchqdeveloper581 · Published 2026-04-29 · Updated 2026-04-30 · CVE-2026-42615

Positive Technologies (AI Summary)

CVSS v3.1

7.2

High

Base vector

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

Name of the Vulnerable Software and Affected Versions GCHQ CyberChef versions prior to 11.0.0

Description Cross-Site Scripting (XSS) is possible via the Show Base64 offsets feature. This occurs through the endpoint '/#recipe=Show Base64 offsets', where an attacker can inject malicious scripts.

Recommendations Update to version 11.0.0 or later.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-42615

GHSA-H4HV-92PP-PCJG

Affected Products

Cyberchef

References · 11

• https://osv.dev/vulnerability/GHSA-h4hv-92pp-pcjg · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-42615 · Security Note
• https://github.com/gchq/CyberChef · Note
• https://github.com/gchq/CyberChef/commit/9641ae07f92e9af50f10e978385465b2f4a36c4d · Note
• https://github.com/gchq/CyberChef/compare/v10.24.0...v11.0.0 · Note
• https://github.com/gchq/CyberChef/pull/2346 · Note
• https://github.com/gchq/CyberChef/issues/2344 · Note
• https://twitter.com/CVEarity/status/2049539245237481502 · Twitter Post
• https://t.me/cveNotify/161588 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2049347535567790181 · Twitter Post
• https://twitter.com/CVEnew/status/2049350420171264009 · Twitter Post