# CVE-2026-86823: Newsletter < 9.3.7 - Unauthenticated Open Redirect and Subscriber Token Disclosure via ncu Parameter

> Unauthenticated attackers can redirect users to malicious sites and disclose subscriber tokens via the ncu parameter in the Newsletter plugin.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-xhvp-v8j9-2mrf

## What is CVE-2026-86823?

CVE-2026-86823 is a medium-severity vulnerability in Unknown Newsletter, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Newsletter  WordPress plugin before 9.3.7 does not validate the destination of the redirect performed after a public subscription action, allowing unauthenticated attackers to redirect users to arbitrary external sites and to disclose a subscriber token that grants access to that subscriber record's front-end actions.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2026-86823?


## How do I fix CVE-2026-86823?

No fix has been published for CVE-2026-86823 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86823 being exploited?

There is no known exploitation of CVE-2026-86823 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86823 and fix it if it is affected.

What it is: CVE-2026-86823 is a medium-severity vulnerability in Unknown Newsletter, published on 16 Sep 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-2026-86823 in the wild and no public exploit code.

Affected product: Unknown Newsletter. 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-2026-86823/ (Markdown: https://insights.sbomify.com/CVE-2026-86823/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86823
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86823
- OSV: https://osv.dev/vulnerability/CVE-2026-86823

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86823/
Summaries are generated and may contain mistakes; the official description above is the record.