High-Severity Missing Authorization Flaw in Shinetheme Traveler WordPress Theme (CVE-2025-26733)

A high-severity vulnerability (CVE-2025-26733) has been identified in the Shinetheme Traveler WordPress theme, affecting versions up to and including 3.1.8. The flaw, classified as a Missing Authorization issue (CWE-862), allows unauthenticated attackers to bypass access controls, potentially modifying sensitive data or performing unauthorized actions. With a CVSS score of 8.2 (High), this vulnerability poses significant risks to WordPress sites using the affected theme.

TL;DR

• CVE ID: CVE-2025-26733
• Affected Product: Shinetheme Traveler WordPress Theme (≤ 3.1.8)
• CVSS Score: 8.2 (High) – AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
• Impact: Unauthenticated attackers can bypass access controls, compromising integrity and availability.
• Status: No fixed version listed; GitHub Advisory marks it as “unreviewed.”

Technical Details

The vulnerability stems from improper access control mechanisms in the Shinetheme Traveler theme, allowing unauthenticated users to perform actions typically restricted to authorized users. The CVSS:3.1 vector breakdown highlights the network-based attack vector (AV:N), low attack complexity (AC:L), and no user interaction required (UI:N). While confidentiality is not impacted (C:N), the integrity (I:H) and availability (A:L) impacts are severe.

Affected Versions

All versions of the Shinetheme Traveler theme up to and including 3.1.8 are vulnerable. The flaw was discovered by Patchstack and documented in a GitHub Advisory^1. Notably, the advisory lacks a fixed version, leaving administrators with limited remediation options beyond removing or restricting the theme.

Exploitation Scenarios

Attackers could exploit this flaw to:

• Modify theme settings or content without authentication.
• Manipulate user-facing elements to inject malicious content.
• Disrupt site functionality by altering critical configurations.

Mitigation and Remediation

Given the lack of a patched version, administrators are advised to:

1. Remove or Disable: Uninstall the Shinetheme Traveler theme if it is not essential.
2. Restrict Access: Implement web application firewalls (WAFs) to block unauthorized requests targeting the theme.
3. Monitor Logs: Review server and application logs for unusual activity, such as unauthorized modification attempts.

Relevance to Security Professionals

For red teams, this vulnerability presents a low-barrier entry point for testing access control weaknesses in WordPress environments. Blue teams should prioritize monitoring for anomalous requests to theme-related endpoints (e.g., /wp-content/themes/traveler/). SOC analysts can use the following Sigma rule to detect potential exploitation attempts:

title: Unauthorized Access to Shinetheme Traveler Endpoints
description: Detects attempts to exploit CVE-2025-26733.
logsource:
  category: web
detection:
  selection:
    uri_path: "/wp-content/themes/traveler/*"
    status_code: 200
    method: POST
  condition: selection

Conclusion

CVE-2025-26733 underscores the persistent risks associated with third-party WordPress themes, particularly those with inadequate access control mechanisms. Organizations using Shinetheme Traveler should act swiftly to mitigate exposure until a patched version becomes available. This vulnerability also highlights the need for rigorous security reviews of WordPress themes before deployment.

References

1. [1]: GitHub Advisory, “GHSA-8w5m-q4c7-vwgq“. [Accessed March 28, 2025].
2. [2]: Patchstack, “WordPress Traveler Theme Broken Access Control“. [Accessed March 28, 2025].
3. [3]: NVD, “CVE-2025-26733“. [Accessed March 28, 2025].