A critical remote code execution (RCE) vulnerability, tracked as CVE-2025-26873, has been disclosed in the Shinetheme Traveler WordPress theme. The flaw, caused by insecure deserialization of untrusted data (CWE-502), affects all versions up to 3.1.8 and carries a CVSS:3.1 score of 9.0 (Critical)^1. Exploitation allows unauthenticated attackers to execute arbitrary code on vulnerable systems, posing significant risks to websites using this theme.
TL;DR Summary
- CVE-2025-26873: Critical (9.0 CVSS) RCE via PHP object injection
- Affected Versions: Shinetheme Traveler ≤ 3.1.8
- Attack Vector: Network-based, no authentication required
- Impact: Full system compromise, data theft, backdoor installation
- Current Status: No patch available as of disclosure (March 27, 2025)
Technical Analysis
The vulnerability stems from improper handling of serialized PHP objects in the Traveler theme. Attackers can craft malicious payloads that, when deserialized, trigger arbitrary code execution. Public proof-of-concept (PoC) exploits have been observed on GitHub and Patchstack^2, increasing the likelihood of active exploitation.
The attack flow typically follows this pattern:
- Attacker sends crafted HTTP request containing malicious serialized object
- Vulnerable theme processes the object during deserialization
- Arbitrary PHP code executes with web server privileges
Detection and Mitigation
Organizations using Shinetheme Traveler should immediately:
| Action | Implementation |
|---|---|
| Version Check | Verify if Traveler theme version ≤ 3.1.8 is installed |
| Workarounds | Disable PHP object deserialization where possible |
| Network Controls | Restrict HTTP PUT/POST methods to trusted sources |
| Monitoring | Audit logs for unusual PHP object deserialization attempts |
Relevance to Security Professionals
This vulnerability presents both offensive and defensive considerations. The availability of public PoCs lowers the barrier for exploitation, while the lack of authentication requirements makes it particularly dangerous for exposed systems. Defenders should prioritize identifying affected installations and implementing compensating controls until an official patch is released.
Conclusion
CVE-2025-26873 represents a severe threat to WordPress installations using the Shinetheme Traveler theme. Organizations should monitor official channels for patch availability while implementing immediate mitigations. The public disclosure of PoC material increases the urgency for remediation efforts.
References
- [1] “CVE-2025-26873 Detail”, CVE Feed. [Accessed March 28, 2025].
- [2] “WordPress Traveler Theme Vulnerability”, Patchstack. [Accessed March 28, 2025].
- [3] “NVD – CVE-2025-26873”, NIST. [Accessed March 28, 2025].
- [4] “GitHub Advisory Database”, GitHub. [Accessed March 28, 2025].
