# Polylang <= 3.8.10 - Authenticated (Editor+) PHP Object Injection via Term Description

- **ID:** WPSEC-2026-0893
- **Plugin:** Polylang (`polylang`), https://wordpress.org/plugins/polylang/
- **Affected versions:** all versions before 3.8.11
- **Fixed in:** 3.8.11 (Update to 3.8.11 or later.)
- **Severity:** Medium 6.6 (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H)
- **Weakness:** CWE-502
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-10-14)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/polylang
- **Fix released:** 2026-10-12
- **Published:** 2026-10-14
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0893/

## Description

The Polylang plugin for WordPress is vulnerable to PHP Object Injection via the descriptions of its language and translation-group taxonomy terms in all versions up to, and including, 3.8.10, due to these descriptions being passed to maybe_unserialize() without restricting allowed classes, and to a disallowed-type check that could be bypassed, for example with leading whitespace. This makes it possible for authenticated attackers, with Editor-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, but if a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

## References

- https://wpsec.com/vuln/WPSEC-2026-0893/
- https://plugins.svn.wordpress.org/polylang/tags/3.8.11/
- https://wordpress.org/plugins/polylang/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0893/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.