CVE-2026-25031: Tasty Daily Object Injection Vulnerability

CVE-2026-25031 Overview

CVE-2026-25031 is a PHP Object Injection vulnerability in the Tasty Daily WordPress theme developed by park_of_ideas. The flaw stems from insecure deserialization of untrusted data [CWE-502] and affects all versions of the theme up to and including 1.27. Unauthenticated attackers can submit crafted serialized payloads to the application over the network. When the theme deserializes this input, attackers can instantiate arbitrary PHP objects and trigger magic methods inside available gadget chains. The result can range from remote code execution to data tampering and full site compromise depending on the classes loaded at runtime.

Critical Impact

Unauthenticated remote attackers can inject malicious PHP objects through the Tasty Daily theme, potentially leading to arbitrary code execution and complete WordPress site takeover.

Affected Products

• park_of_ideas Tasty Daily WordPress theme — all versions through 1.27
• WordPress sites using the tastydaily theme slug
• Any deployment exposing the vulnerable deserialization sink to the network

Discovery Timeline

• 2026-03-25 - CVE-2026-25031 published to NVD
• 2026-04-24 - Last updated in NVD database

Technical Details for CVE-2026-25031

Vulnerability Analysis

The Tasty Daily theme passes attacker-controlled input to a PHP deserialization function without validating its origin or structure. PHP's unserialize() rebuilds objects from a string representation and invokes magic methods such as __wakeup, __destruct, or __toString during reconstruction. When attacker-supplied serialized data reaches this sink, the attacker chooses which classes are instantiated and which properties those classes hold.

Exploitation does not require authentication or user interaction, and the attack is reachable across the network. The theme alone may not include a usable gadget chain, but WordPress core, plugins, and other themes commonly load classes that complete a chain leading to file writes, SQL queries, or command execution. This pattern is consistent with prior PHP Object Injection issues tracked under [CWE-502].

Root Cause

The root cause is the use of native PHP deserialization on input that crosses a trust boundary. The theme treats serialized data such as cookie values, request parameters, or option fields as safe and reconstructs objects from it. No allowlist of classes, no integrity check, and no signed payload mechanism guards the call.

Attack Vector

An attacker delivers a serialized PHP payload to a vulnerable endpoint exposed by the Tasty Daily theme. The payload encodes objects whose properties drive a gadget chain present in the loaded codebase. On deserialization, PHP triggers magic methods on these objects and the chain executes attacker-chosen behavior. Refer to the Patchstack Vulnerability Report for the disclosed attack surface.

Detection Methods for CVE-2026-25031

Indicators of Compromise

• HTTP requests to WordPress endpoints containing serialized PHP markers such as O:, a:, or s: followed by class names and lengths.
• Unexpected PHP files written under wp-content/themes/tastydaily/, wp-content/uploads/, or other web-writable directories.
• New or modified WordPress administrator accounts and unexpected scheduled tasks in wp_options (cron).
• Outbound connections from the PHP worker process to unfamiliar hosts shortly after suspicious POST requests.

Detection Strategies

• Inspect web server access logs for POST and GET parameters matching PHP serialization syntax targeting the Tasty Daily theme.
• Monitor PHP process behavior for child process creation, especially shells spawned from php-fpm or the web server user.
• Alert on file integrity changes within active WordPress theme and plugin directories.

Monitoring Recommendations

• Enable WordPress audit logging for option changes, user role changes, and theme or plugin installations.
• Forward web server, PHP error, and WAF logs to a centralized SIEM for correlation across the request, process, and file layers.
• Track outbound network connections from web hosts and flag deviations from established baselines.

How to Mitigate CVE-2026-25031

Immediate Actions Required

• Take the Tasty Daily theme offline or switch to a default WordPress theme until a fixed version is confirmed.
• Audit the WordPress installation for unauthorized administrator accounts, modified wp-config.php, and unknown PHP files.
• Rotate WordPress secret keys, database credentials, and administrator passwords if compromise is suspected.

Patch Information

No fixed version is listed in the available advisory data. The vulnerability affects Tasty Daily through version 1.27. Consult the Patchstack Vulnerability Report for the latest vendor status and apply any released update from park_of_ideas as soon as it becomes available.

Workarounds

• Deploy a web application firewall rule that blocks request parameters containing PHP serialization signatures such as O: and a: followed by class metadata.
• Restrict access to WordPress administrative and theme-handled endpoints by source IP where feasible.
• Replace the Tasty Daily theme with a maintained alternative if a patch is not released in a reasonable timeframe.

# Example ModSecurity rule to block PHP serialized object payloads
SecRule ARGS|ARGS_NAMES|REQUEST_COOKIES "@rx (?:^|[^a-zA-Z0-9])O:\d+:\"[a-zA-Z_\\\\]+\":\d+:\{" \
    "id:1002601,phase:2,deny,status:403,log,\
    msg:'Possible PHP Object Injection payload (CVE-2026-25031)',\
    tag:'CWE-502'"