CleanSkin WordPress theme: Unauthenticated PHP Object Injection
Summary
The CleanSkin WordPress theme up to and including version 1.5.0 is vulnerable to unauthenticated PHP Object Injection (CWE-502). An unauthenticated remote attacker can supply crafted serialized data to a public-facing website, which may allow manipulation of server-side processing and, depending on the classes available in the installed plugins and WordPress core, further harmful actions on the server. The CNA rates the issue CVSS 9.8 (critical), and Patchstack expects exploitation, but no known exploitation or public proof of concept was found at the time of research.
Affected
- CleanSkin theme 1.5.0 and earlier (all installations, per the Patchstack record)
- Bundled Slider Revolution plugin: version not verified
Fixed in
Unknown. No fixed version is published in the sources reviewed. Newer ThemeForest releases exist, but it is not confirmed whether they fix this issue.
Workaround
- Unknown. No vendor workaround is documented.
- Deactivate and remove the theme if it is not in use.
- Apply a WAF rule or virtual patch if your hosting provider offers one.
Exploitation
- Known exploited: No (not in CISA KEV according to the sources reviewed).
- Public proof of concept: None found in the search performed.
- CISA SSVC: Exploitation none, automatable yes, technical impact total.
- EPSS: around 0.004 (very low), per Vulners.
Our recommendation
- Check the installed CleanSkin version in WordPress under Appearance > Themes.
- Update to the latest release from ThemeForest and confirm in the changelog that this issue is fixed.
- Check the Slider Revolution plugin version and update it as well.
- If no fixed version is available, deactivate the theme and restrict access with a WAF or virtual patch.
- Create a backup and check for unexpected administrator accounts and file changes.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Patchstack advisory patchstack.com
- OpenCVE CVE-2026-42723 app.opencve.io
- Vulners CVE-2026-42723 vulners.com
- HOL Guard CVE-2026-42723 hol.org
- Strix CVE-2026-42723 www.strix.ai
- ThemeForest CleanSkin theme themeforest.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, 19:42.
Original description (NVD)
Unauthenticated PHP Object Injection in CleanSkin <= 1.5.0 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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