Is CVE-2026-7637 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-7637 being exploited in the wild.

How severe is CVE-2026-7637?

Critical severity, with a CVSS score of 9.8, published 20 May 2026.

Which products and versions are affected?

PixelYourSite Boost up to, and including, 2.0.3.

Is there a fix for CVE-2026-7637?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-7637 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-7637?

Check whether you run PixelYourSite Boost at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-7637: PixelYourSite Boost PHP object injection in STYXKEY-BOOST_USER_LOCATION cookie

CVE-2026-7637 · Severity: critical · CVSS 9.8 · Published 2026-05-20

The Boost plugin for WordPress, which is used to optimize site performance, contains a security flaw that allows unauthorized users to inject malicious code. By sending a specially crafted browser cookie, an attacker could potentially take control of the website, delete files, or steal sensitive information. This risk is particularly high if the website also uses other plugins or themes with specific underlying vulnerabilities that the attacker can chain together.

Vendors: PixelYourSite.

Quick answers

Is CVE-2026-7637 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-7637 being exploited in the wild.
How severe is CVE-2026-7637?: Critical severity, with a CVSS score of 9.8, published 20 May 2026.
Which products and versions are affected?: PixelYourSite Boost up to, and including, 2.0.3.
Is there a fix for CVE-2026-7637?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-7637 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-7637?: Check whether you run PixelYourSite Boost at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a PHP Object Injection flaw (CWE-502) residing in the Boost plugin for WordPress. The root cause is the unsafe deserialization of user-supplied data provided through the 'STYXKEY-BOOST_USER_LOCATION' cookie. An unauthenticated remote attacker can exploit this by sending a crafted request containing a serialized PHP object. While the plugin itself does not contain a known Property-Oriented Programming (POP) chain, the vulnerability can be weaponized if another installed plugin or theme provides a POP chain. Successful exploitation could lead to arbitrary file deletion, sensitive data retrieval, or remote code execution depending on the available chains. The issue affects all versions up to and including 2.0.3.

Affected products

PixelYourSite Boost up to, and including, 2.0.3

Timeline

2026-05-20: disclosed: CVE published to the NVD dataset.

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.