Jetpack – WP Security, Backup, Speed, & Growth 16.1 - 16.1.2 - Authenticated (Administrator+) PHP Object Injection

2026-09-05 00:00
Jetpack

Strategic Overview

Status
Patched in 16.1.3
Affected Version
16.1 – 16.1.2
CVSS
6.6Medium
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE pending
View all Jetpack – WP Security, Backup, Speed, & Growth vulnerabilities

At a glance

This record tracks a medium-severity Deserialization of Untrusted Data vulnerability in the Jetpack WordPress plugin, affecting versions 16.1 – 16.1.2. It carries a CVSS score of 6.6 (reachable over the network; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Administrator level or above. The issue is fixed in version 16.1.3; sites on affected versions should update now. Disclosed September 2026, reported by Jetpack.

Vulnerability Overview

The Jetpack – WP Security, Backup, Speed, & Growth plugin for WordPress is vulnerable to PHP Object Injection in versions 16.1 through 16.1.2. This is due to deserialization of untrusted input. This makes it possible for authenticated attackers, with administrator-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software. 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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-502: Deserialization of Untrusted Data

Reaching this weakness in Jetpack 16.1 – 16.1.2 takes an account at Administrator level or above. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.

A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For Jetpack the fix is 16.1.3: builds 16.1 – 16.1.2 are affected, anything from 16.1.3 onward is not.

Remediation

Update to version 16.1.3, or a newer patched version

How does WordSec protect against this?

An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Jetpack 16.1.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

Related records

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