CVE-2026-83628
MediumCVSS 4.3Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
The Theme My Login plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 7.1.15 on Multisite installations. This is due to the `tml_ms_signup_handler()` function's `gimmeanotherblog` branch failing to enforce the network's `active_signup` registration policy, checking only `is_user_logged_in()` while sibling branches such as `validate-blog-signup` apply the full policy gate. This allows authenticated attackers with Subscriber-level access and above to directly POST `stage=gimmeanotherblog` to Theme My Login's signup route, bypassing the configured registration policy entirely — even when it is set to `none` or `user` — which causes `wpmu_create_blog()` to execute with the attacker's user ID, after which WordPress core assigns the Administrator role on the newly created subsite. The privilege gain is scoped to the newly created subsite only; the attacker's account retains Subscriber-level access on the main site and does not obtain Super Admin or network-level capabilities.
Risk Assessment
The risk includes unauthorized creation of subsites and privilege escalation within new subsites, which could lead to distribution of malicious content or further attacks.
Recommendation
Update the plugin to the latest patched version. Also carefully configure registration policies and monitor newly created subsites.
Other vulnerabilities in Theme My Login
See all- CVE-2026-89079Critical
The Theme My Login plugin for WordPress is vulnerable to privilege escalation via account takeover in versions up to, and including, 7.2.1. This is due to the plugin not properly validating a user's identity prior to updating their password, allowing unauthenticated attackers to change arbitrary user's passwords on multi-site setups in certain configurations.
- CVE-2026-66681Medium
CSRF vulnerability in Theme My Login versions up to 7.1.14 allows an unauthenticated attacker to perform unauthorized actions.
Original NVD description (English source)
The Theme My Login plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 7.1.15 on Multisite installations. This is due to the `tml_ms_signup_handler()` function's `gimmeanotherblog` branch failing to enforce the network's `active_signup` registration policy, checking only `is_user_logged_in()` while sibling branches such as `validate-blog-signup` apply the full policy gate. This makes it possible for authenticated attackers, with Subscriber-level access and above, to directly POST `stage=gimmeanotherblog` to Theme My Login's signup route, bypassing the configured registration policy entirely — even when it is set to `none` or `user` — which causes `wpmu_create_blog()` to execute with the attacker's user ID, after which WordPress core assigns the Administrator role on the newly created subsite via `add_user_to_blog()`. The privilege gain is scoped to the newly created subsite only; the attacker's account retains Subscriber-level access on the main site and does not obtain Super Admin or network-level capabilities such as `manage_network` or `manage_sites`.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS