How severe is CVE-2026-7637?

CVE-2026-7637 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-7637 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-7637?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-7637 have an EU (EUVD) identifier?

Yes. CVE-2026-7637 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31045.

When was CVE-2026-7637 published?

CVE-2026-7637 was published on 2026-05-20 and last updated on 2026-06-17.

CVE-2026-7637

CVE-2026-7637 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31045
Weakness: CWE-502
Published: 2026-05-20
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-7637?: 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.
How severe is CVE-2026-7637?: CVE-2026-7637 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-7637 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-7637?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-7637 have an EU (EUVD) identifier?: Yes. CVE-2026-7637 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31045.
When was CVE-2026-7637 published?: CVE-2026-7637 was published on 2026-05-20 and last updated on 2026-06-17.

References

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