CVE-2026-1729: Critical Authentication Bypass in the AdForest WordPress Theme (CVSS 9.8)
A critical security vulnerability has been identified in the AdForest WordPress theme. Tracked as CVE-2026-1729, this issue allows unauthenticated users to bypass authentication and log in as any existing account, including administrators.
The vulnerability affects all versions up to and including 6.0.12 and has received a CVSS 3.1 score of 9.8 (Critical).
For sites running this theme, the risk is significant.
What Is the AdForest Theme?
AdForest is a commercial WordPress theme designed for building classified ads and directory style websites. It is commonly used for:
- Buy and sell marketplaces
- Local classified listings
- Automotive and real estate ads
- General listing platforms
The theme includes built-in account management, posting systems, monetization tools, and messaging features. Because it handles user authentication and permissions, its security controls are especially important.
What Is CVE-2026-1729?
The vulnerability is located in a function named:
sb_login_user_with_otp_fun
This function was intended to authenticate users through a one-time password system. However, the implementation did not properly verify user identity before completing the login process.
As a result, authentication checks could be bypassed entirely. An unauthenticated party could gain access to arbitrary user accounts without providing valid credentials.
If the targeted account has administrator privileges, the entire site can be compromised.
CVSS Score Explanation
The vulnerability carries the following CVSS 3.1 vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
In practical terms, this means:
- It can be exploited remotely over the network
- It is easy to exploit
- No prior privileges are required
- No user interaction is necessary
- The impact to confidentiality, integrity, and availability is high
A 9.8 rating reflects the highest level of severity short of a maximum score.
Potential Impact
If a vulnerable site is compromised, an attacker with administrative access could:
- Modify or delete site content
- Install malicious plugins or backdoors
- Create hidden administrator accounts
- Access or exfiltrate user data
- Redirect visitors
- Inject malware
Because WordPress permissions are role-based, obtaining administrator access effectively grants full control of the website.
Recommended Actions
If you are using the AdForest theme:
- Verify your installed version. Versions 6.0.12 and earlier are affected.
- Update immediately to the patched release provided by the vendor.
- Review administrative user accounts for unfamiliar entries.
- Check for unexpected file modifications or newly installed plugins.
- Rotate administrative credentials if compromise is suspected.
Given the severity of this issue, prompt remediation is strongly advised.
Security Takeaway
Authentication logic is one of the most sensitive areas in any application. Even small validation gaps can undermine the entire security model. Themes and plugins that implement custom login or OTP functionality must ensure strict server-side verification and proper permission checks.
CVE-2026-1729 serves as a reminder that third-party components should be monitored closely and updated without delay when critical vulnerabilities are disclosed.