# CVE-2023-5958: POST SMTP Mailer < 2.7.1 - Unauthenticated Cross-site Scripting

> Unauthenticated attackers can inject malicious scripts via email content, potentially compromising highly privileged admin accounts in the POST SMTP Mailer plugin.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Nov 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-2r79-jc6j-hh65

## What is CVE-2023-5958?

CVE-2023-5958 is a medium-severity cross-site scripting vulnerability in Unknown POST SMTP Mailer, published on 27 Nov 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The POST SMTP Mailer WordPress plugin before 2.7.1 does not escape email message content before displaying it in the backend, allowing an unauthenticated attacker to perform XSS attacks against highly privileged users.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2023-5958?

It affects 1 product.


Products: Wpexperts Post Smtp.

## How do I fix CVE-2023-5958?

No fix has been published for CVE-2023-5958 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-5958 being exploited?

There is no known exploitation of CVE-2023-5958 in the wild and no public exploit code.

## Other vulnerabilities in Unknown POST SMTP Mailer

- [CVE-2023-6875](https://insights.sbomify.com/CVE-2023-6875/): Auth bypass in Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App (critical 9.8)
- [CVE-2023-3179](https://insights.sbomify.com/CVE-2023-3179/): POST SMTP Mailer < 2.5.7 - Account Takeover via CSRF (high 8.8)
- [CVE-2023-52233](https://insights.sbomify.com/CVE-2023-52233/): WordPress POST SMTP Mailer plugin <= 2.8.6 - Broken Access Control on API vulnerability (high 8.6)
- [CVE-2024-52436](https://insights.sbomify.com/CVE-2024-52436/): WordPress Post SMTP plugin <= 2.9.9 - SQL Injection vulnerability (high 7.6)
- [CVE-2025-0521](https://insights.sbomify.com/CVE-2025-0521/): Post SMTP <= 3.0.2 - Unauthenticated Stored Cross-Site Scripting (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-5958 and fix it if it is affected.

What it is: CVE-2023-5958 is a medium-severity cross-site scripting vulnerability in Unknown POST SMTP Mailer, published on 27 Nov 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-5958 in the wild and no public exploit code.

Affected product: Unknown POST SMTP Mailer. 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-2023-5958/ (Markdown: https://insights.sbomify.com/CVE-2023-5958/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-5958
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-5958
- OSV: https://osv.dev/vulnerability/CVE-2023-5958

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-5958/
Summaries are generated and may contain mistakes; the official description above is the record.