Cross-site scripting in Ghost - CVE-2026-53950
Published: July 30, 2026
Vulnerability identifier: #VU140542
CSH Severity: Medium
CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-53950
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject arbitrary JavaScript.
The vulnerability exists due to cross-site scripting in the ActivityPub client when processing posts shared by a maliciously customised ActivityPub server. A remote attacker can share a specially crafted post to inject arbitrary JavaScript.
User interaction is required.
Affected software
Ghost
How to mitigate CVE-2026-53950
Install security update from vendor's website.
Ghost - update to 3.1.0