GS Testimonial Slider WordPress plugin: PHP Object Injection by Contributor
Summary
The WordPress plugin GS Testimonial Slider up to and including version 3.3.10 contains a PHP Object Injection vulnerability (CWE-502, deserialization of untrusted data). An authenticated user with at least Contributor rights can send crafted data that the plugin deserializes, which may allow manipulation of server-side processing. The CVSS base score is 8.8 and the vector rates confidentiality, integrity and availability impact as high, but the actual impact depends on the code paths and POP chains present on the site, which could not be verified.
Affected
- GS Testimonial Slider plugin for WordPress, versions up to and including 3.3.10
- Attacker requires an account with at least Contributor role
Fixed in
Unknown. No patched version has been confirmed by the vendor or Patchstack.
Workaround
- Deactivate and remove the plugin on sites where it is not needed
- Review and restrict the Contributor role, remove unused accounts and check for recent contributor activity
- Consider a virtual patch from a WAF or vulnerability-shield service until a fixed version is confirmed; coverage for this CVE is not verified
Exploitation
- Not known to be exploited in the wild
- Not listed in CISA KEV
- No public proof-of-concept found
- CISA SSVC: exploitation none, automatable no, technical impact total
- EPSS: not yet published
Our recommendation
- Inventory all WordPress sites with this plugin and record exact versions
- Deactivate and remove the plugin where it is not required
- Review Contributor and other user accounts, enforce strong unique passwords and disable open registration where possible
- Monitor the Patchstack page and NVD for a fixed version and update as soon as one is published
- Priority: high for inventory and access review, medium for exploitation risk until a fix is verified
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Patchstack advisory CVE-2026-78527 patchstack.com
- VulDB entry 429300 vuldb.com
- Vulners PT-2026-133792 vulners.com
- Strix AI CVE summary www.strix.ai
- OffSeq Radar threat entry radar.offseq.com
- Patchstack earlier XSS advisory (3.1.4) patchstack.com
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 31 Oct 2026, 08:41.
Original description (NVD)
Contributor PHP Object Injection in GS Testimonial Slider <= 3.3.10 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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