CVE-2026-27084
Deserialization Object Injection in ThemeREX Buisson
Publication date: 2026-03-25
Last updated on: 2026-04-23
Assigner: Patchstack
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| themerex | buisson | to 1.1.11 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-502 | The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-27084 is a high-priority PHP Object Injection vulnerability affecting the WordPress Buisson Theme versions up to and including 1.1.11.
This vulnerability allows unauthenticated attackers to perform PHP Object Injection, which can lead to various attacks such as code injection, SQL injection, path traversal, denial of service, and others if a suitable Property Oriented Programming (POP) chain is present.
The vulnerability falls under the OWASP Top 10 category A3: Injection and requires no privileges to exploit.
How can this vulnerability impact me? :
This vulnerability can have severe impacts including unauthorized code execution, database compromise through SQL injection, unauthorized file access via path traversal, and denial of service attacks.
Since it requires no privileges to exploit, attackers can leverage this vulnerability without authentication, increasing the risk to affected websites.
These impacts can lead to data breaches, website downtime, and potential loss of control over the affected system.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
CVE-2026-27084 is a PHP Object Injection vulnerability affecting the WordPress Buisson Theme up to version 1.1.11. Detection typically involves monitoring for exploitation attempts targeting this vulnerability.
Patchstack has released a mitigation rule that blocks exploitation attempts, which can be used to detect suspicious activity related to this vulnerability.
While no specific commands are provided in the available resources, users can monitor web server logs for unusual requests or payloads attempting PHP Object Injection patterns targeting the Buisson theme.
Additionally, using web application firewalls (WAFs) with rules from Patchstack or similar security providers can help detect and block exploitation attempts.
What immediate steps should I take to mitigate this vulnerability?
Since no official patch is currently available for the Buisson theme, immediate mitigation steps include applying the Patchstack mitigation rule that blocks exploitation attempts.
Users are advised to update the theme as soon as an official patch is released.
In the meantime, seek assistance from hosting providers or developers to apply available mitigations or security controls such as web application firewalls.
Monitoring and restricting access to the vulnerable theme files and limiting exposure to unauthenticated users can also reduce risk.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows unauthenticated attackers to perform PHP Object Injection, potentially leading to code injection, SQL injection, path traversal, denial of service, and other attacks. Such impacts can compromise the confidentiality, integrity, and availability of data.
Given the high severity and potential for data breaches, this vulnerability could negatively affect compliance with common standards and regulations like GDPR and HIPAA, which require protection of sensitive data and maintaining system security to prevent unauthorized access or data leakage.
However, no explicit mention of compliance impact is provided in the available resources.