# CVE-2026-15964: Single Sign On For TNG <= 2.0.0 - Unauthenticated Privilege Escalation via Unverified Password Change

> Unauthenticated attackers can reset any user's password, including administrators, by exploiting a publicly exposed nonce in the Single Sign On For TNG plugin.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Aug 2026
- **Updated:** 3 Aug 2026
- **Also known as:** GHSA-75h6-5h53-j8cq

## What is CVE-2026-15964?

CVE-2026-15964 is a critical authentication bypass vulnerability in britcoder Single Sign On For TNG, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Single Sign On For TNG plugin for WordPress is vulnerable to Authentication Bypass via unauthenticated password reset in all versions up to, and including, 2.0.0. This is due to the `ssoprocess_ajax()` function — registered on `wp_ajax_nopriv_ssoprocess_ajax` and therefore reachable without authentication — accepting an attacker-supplied `email` parameter with the `setnewpassword` operation and calling `reset_password()` on the resolved account without any ownership token, email confirmation link, or capability check. The sole guard is a call to `check_ajax_referer()`, which provides no authorization barrier because the `ssoajaxnonce` nonce is publicly broadcast on every front-end page via `wp_localize_script()` into the `SSOPWDREQUIREMENT` JavaScript object; since WordPress computes nonces for logged-out visitors against a shared anonymous session context, any unauthenticated visitor can scrape a valid nonce from the homepage and use it to authenticate the request. This makes it possible for unauthenticated attackers to change the password of any WordPress account, including administrator accounts, enabling complete site takeover.

Weakness: CWE-620 (Unverified Password Change)

## Which versions are affected by CVE-2026-15964?


## How do I fix CVE-2026-15964?

No fix has been published for CVE-2026-15964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15964 being exploited?

There is no known exploitation of CVE-2026-15964 in the wild and no public exploit code.

Public exploit code:

- PoC & checker for CVE-2026-15964 - unauthenticated password change in the WordPress plugin Single Sign On For TNG <= 2.0.0 (CVSS 9.8) (github_poc): https://github.com/Instructor-Admin/CVE-2026-15964-PoC

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15964 and fix it if it is affected.

What it is: CVE-2026-15964 is a critical authentication bypass vulnerability in britcoder Single Sign On For TNG, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15964 in the wild and no public exploit code.

Affected product: britcoder Single Sign On For TNG. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15964/ (Markdown: https://insights.sbomify.com/CVE-2026-15964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15964
- OSV: https://osv.dev/vulnerability/CVE-2026-15964

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-15964/
Summaries are generated and may contain mistakes; the official description above is the record.