CVE-2025-52826: Sala Object Injection Vulnerability

CVE-2025-52826 Overview

CVE-2025-52826 is a PHP Object Injection vulnerability in the uxper Sala WordPress theme. The flaw stems from deserialization of untrusted data [CWE-502] and affects all versions of Sala up to and including 1.1.3. An authenticated attacker with low privileges can supply crafted serialized input that the theme processes through an unsafe unserialize() call. Successful exploitation leads to arbitrary PHP object instantiation, which can chain into remote code execution when suitable gadget chains exist in the WordPress environment.

Critical Impact
Authenticated attackers with low privileges can trigger PHP object injection, potentially leading to remote code execution, full site compromise, and exposure of confidential WordPress data.

Affected Products

uxper Sala WordPress theme versions through 1.1.3
WordPress installations running the vulnerable Sala theme
Sites where untrusted users have authenticated access at any privilege level

Discovery Timeline

2025-06-27 - CVE-2025-52826 published to the National Vulnerability Database (NVD)
2026-04-28 - Last updated in NVD database

Technical Details for CVE-2025-52826

Vulnerability Analysis

The vulnerability resides in the Sala theme's handling of serialized PHP data. The theme passes attacker-controlled input into a PHP deserialization routine without validation or type restriction. When PHP deserializes this input, it reconstructs arbitrary objects and invokes magic methods such as __wakeup() and __destruct() during object lifecycle events.

The attack vector is network-based and requires low-privilege authentication. No user interaction is required. The scope is unchanged, but confidentiality, integrity, and availability are all impacted at a high level.

The Patchstack advisory lists the issue as a PHP Object Injection vulnerability that affects Sala versions through 1.1.3. Exploitation depends on suitable gadget chains, which are widely available in WordPress core, popular plugins, and PHP libraries.

Root Cause

The root cause is unsafe use of PHP's unserialize() function on data sourced from user-controllable input. The theme does not validate, sign, or restrict allowed classes before deserialization. This violates secure deserialization practices defined under [CWE-502: Deserialization of Untrusted Data].

Attack Vector

An authenticated attacker submits a crafted serialized PHP payload through a Sala theme endpoint that performs deserialization. The payload references PHP classes that contain exploitable magic methods. When the object is reconstructed, the magic methods execute attacker-defined logic. Depending on available gadget chains, the attacker can read or write files, execute arbitrary code, or escalate privileges within WordPress.

No public proof-of-concept exploit code is currently referenced in the CVE data. Refer to the Patchstack Vulnerability Report for technical details.

Detection Methods for CVE-2025-52826

Indicators of Compromise

HTTP requests to Sala theme endpoints containing serialized PHP markers such as O:, a:, or s: patterns in parameters
Unexpected PHP files appearing under the WordPress webroot, including wp-content/uploads/ directories
New or modified administrator accounts created without authorized change records
Outbound network connections from the PHP worker process to unknown hosts following theme requests

Detection Strategies

Inspect web server access logs for POST requests to Sala theme handlers containing serialized object syntax
Monitor PHP error logs for __wakeup, __destruct, or class instantiation failures originating from theme code
Apply Web Application Firewall (WAF) rules that block serialized PHP payloads in untrusted parameters
Correlate authenticated low-privilege user sessions with administrative file changes

Monitoring Recommendations

Enable file integrity monitoring on the wp-content/themes/sala/ directory and WordPress core files
Forward WordPress and web server logs to a centralized analytics platform for cross-source correlation
Alert on PHP process spawning shell utilities such as sh, bash, curl, or wget

How to Mitigate CVE-2025-52826

Immediate Actions Required

Identify all WordPress sites running the Sala theme version 1.1.3 or earlier
Restrict access to WordPress authenticated endpoints until a patched version is deployed
Rotate WordPress administrator credentials and audit user accounts for unauthorized additions
Review web server logs for suspicious serialized payloads since June 2025

Patch Information

At the time of CVE publication, no fixed version is referenced in the available NVD or Patchstack data. Site operators should consult the Patchstack Vulnerability Report for the latest vendor guidance and updated theme releases.

Workarounds

Deactivate the Sala theme and switch to an unaffected theme until a patch is available
Deploy WAF rules that block requests containing PHP serialized object syntax in parameter values
Limit account creation and enforce least-privilege roles to reduce the pool of authenticated attackers
Disable PHP functions used in common gadget chains where application functionality permits

bash

# Example WAF rule (ModSecurity) to block serialized PHP objects in request bodies
SecRule REQUEST_BODY "@rx (?:^|&)[^=]+=O:\d+:\"[A-Za-z0-9_\\\\]+\":\d+:" \
    "id:1005282,phase:2,deny,status:403,log,msg:'Possible PHP Object Injection (CVE-2025-52826)'"