# CVE-2026-48838: WPExperts Post SMTP unauthenticated XSS

Source: https://junglewise.ai/threats/cve-2026-48838-wpexperts-post-smtp-unauthenticated-xss  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-15. Updated: 2026-06-15  
License: CC BY 4.0 with a link back

CVE-2026-48838 · Severity: high · CVSS 7.1 · Published 2026-06-15

Post SMTP is a popular WordPress plugin used to manage and deliver emails from a website. A security flaw allows an unauthenticated attacker to inject malicious scripts into the site, which could lead to unauthorized actions or data theft when an administrator visits the dashboard. This could result in a full site takeover if a high-privileged user is targeted.

Vendors: [WPExperts](https://junglewise.ai/threats/vendors/wpexperts).

## Quick answers

**Is CVE-2026-48838 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48838 being exploited in the wild.

**How severe is CVE-2026-48838?** High severity, with a CVSS score of 7.1, published 15 June 2026.

**Which products and versions are affected?** WPExperts Post SMTP <= 3.6.2.

**Is there a fix for CVE-2026-48838?** A patch was published on 2026-05-28: Patch released in version 3.6.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48838 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-48838?** Check whether you run WPExperts Post SMTP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A reflected Cross-Site Scripting (XSS) vulnerability exists in the Post SMTP plugin for WordPress due to improper neutralization of input during web page generation (CWE-79). The vulnerability affects versions up to and including 3.6.2. An unauthenticated attacker can exploit this by tricking a privileged user (such as an administrator) into clicking a specially crafted link or visiting a malicious page. Successful exploitation allows the execution of arbitrary JavaScript in the context of the victim's browser session, potentially leading to session hijacking or administrative account takeover. The issue is resolved in version 3.6.3.

## Affected products

- WPExperts Post SMTP <= 3.6.2

## Timeline

- 2025-11-14: other: Vulnerability reported by researcher mcdruid
- 2026-05-28: patched: Patch released in version 3.6.3
- 2026-06-15: advisory: CVE published to NVD

## References

- [https://patchstack.com/database/wordpress/plugin/post-smtp/vulnerability/wordpress-post-smtp-plugin-3-6-2-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/post-smtp/vulnerability/wordpress-post-smtp-plugin-3-6-2-cross-site-scripting-xss-vulnerability?_s_id=cve)

## Related threats

- [WPExperts Post SMTP missing authorization in settings management](https://junglewise.ai/threats/cve-2026-81278-wpexperts-post-smtp-missing-authorization-in-settings-management)