Alliance WordPress theme: PHP object injection without authentication
Summary
The ThemeREX Alliance WordPress theme up to and including version 3.11 contains a PHP object injection vulnerability (CWE-502). An unauthenticated remote attacker can send crafted data that the site unserializes, which can manipulate application logic and, depending on the code available in the installed components, lead to code execution on the server. The CVSS 3.1 base score is 9.8 (critical). Internet-facing and extranet sites running this theme are most at risk.
Affected
- ThemeREX Alliance WordPress theme, all versions up to and including 3.11
Fixed in
Unknown. No confirmed fixed version has been published. Do not assume that newer versions are fixed until the vendor confirms it.
Workaround
- No vendor workaround published.
- Restrict access to the site (IP allowlist, VPN or basic authentication) until a fix is confirmed.
- Use a WordPress-aware WAF with virtual patching if available.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC rating: exploitation none, automatable yes (a rating, not evidence of observed attacks).
- EPSS 0.00304 (low). No public proof of concept or in-the-wild exploitation found at the time of research.
Our recommendation
- Inventory all WordPress sites using Alliance and record the installed version.
- Treat all versions up to 3.11 as vulnerable.
- Restrict access to intranet/extranet sites and enable WAF virtual patching.
- If no fixed version is confirmed, plan to replace the theme with a maintained one, after taking a full backup.
- Review the site for unexpected admin accounts and modified files, and monitor the vendor and NVD for updates.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Patchstack: WordPress Alliance theme <= 3.11 PHP Object Injection patchstack.com
- OpenCVE: CVE-2026-78529 app.opencve.io
- Vulners (Rapid7): CVE-2026-78529 vulners.com
- VulDB: CVE-2026-78529 vuldb.com
- ThemeForest: Alliance Intranet & Extranet WordPress Theme themeforest.net
- ThemeREX Alliance documentation doc.themerex.net
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 19:25.
Original description (NVD)
Unauthenticated PHP Object Injection in Alliance <= 3.11 versions.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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