CVE-2026-7637CWE-502

Boost <= 2.0.3 - Unauthenticated PHP Object Injection via STYXKEY-BOOST_USER_LOCATION Cookie

Critical · published May 20, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
54.7
In the wild
Unconfirmed
What it is

The Boost plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.0.3 via deserialization of untrusted input in the STYXKEY-BOOST_USER_LOCATION cookie. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00757 · 54.7th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-05-20T02:27Z
EPSS history
Timeline
  • 20 MAY 02:27Z
    Boost <= 2.0.3 - Unauthenticated PHP Object Injection via STYXKEY-BOOST_USER_LOCATION Cookie
    cvelistv5