CVE-2026-19658: Give Tributes WordPress Plugin PHP Object Injection (CVSS 9.8) — Detection and Remediation Guide

NVD has published CVE-2026-19658, a CVSS 9.8 (CRITICAL) vulnerability in the Give Tributes plugin for WordPress, affecting all versions up to and including 2.3.1. The flaw is a PHP Object Injection caused by deserialization of untrusted input, and it is exploitable remotely over the network without authentication. That combination — unauthenticated, network-reachable, CVSS 9.8 — puts this squarely in the top tier of WordPress plugin risks for 2026.

There is one important nuance defenders must understand before triaging: no POP (Property-Oriented Programming) chain exists in the vulnerable plugin itself. On a clean install running only Give Tributes, an injected object has limited practical impact. But WordPress sites almost never run a single plugin. If any other installed plugin or theme contains an exploitable POP chain — and in the WordPress ecosystem, many do — the attacker-controlled object can be weaponized into arbitrary file deletion, sensitive data retrieval, and potentially remote code execution. Treat this as a real-world RCE precursor, not a theoretical bug.

Technical Analysis

Affected Product

• Product: Give Tributes plugin for WordPress
• Affected versions: All versions ≤ 2.3.1
• Vulnerability class: CWE-502 — Deserialization of Untrusted Data
• CVE: CVE-2026-19658, CVSS 3.1 score 9.8 (CRITICAL), attack vector NETWORK
• Authentication required: None
• Reference: https://nvd.nist.gov/vuln/detail/CVE-2026-19658

How the Vulnerability Works

The plugin passes attacker-controllable input into PHP's unserialize() (or an equivalent deserialization path) without adequate validation. PHP serialization preserves object types: when an attacker submits a crafted serialized string such as O:8:"SomeClass":..., PHP instantiates the named class during deserialization. That instantiation triggers the class's magic methods — __wakeup(), __destruct(), __toString() — and that's where exploitation lives.

A POP chain is a sequence of classes, already present in the codebase of an installed plugin or theme, whose magic methods can be chained together so that instantiating one object cascades into dangerous operations: writing files, deleting files via unlink(), reading arbitrary files, or invoking call_user_func() on attacker-controlled arguments. The classic real-world outcome of a WordPress PHP Object Injection plus an available POP chain is:

1. Unauthenticated request to a plugin endpoint (AJAX handler, REST route, or form processor) carrying a serialized payload in a parameter.
2. Object instantiation of a class from a different plugin/theme that has a usable magic method.
3. Arbitrary file deletion (e.g., deleting wp-config.php to force re-installation and site takeover) or arbitrary file read (dumping database credentials).
4. Where a code-execution chain exists, full RCE as the web server user (www-data/apache), followed by web shell deployment, lateral movement into the database, and site persistence via injected admin accounts or modified theme files.

Exploitation Status

As of this writing, there is no confirmed in-the-wild exploitation and the CVE has not been added to CISA's Known Exploited Vulnerabilities catalog. However, the absence of a POP chain in the plugin itself should not lull anyone into complacency. Historically, WordPress object-injection bugs get weaponized within days of public disclosure because scanners can fingerprint vulnerable plugin versions trivially, and commodity POP chains for popular plugins are documented publicly. Assume active scanning is imminent if not already underway.

Detection & Response

Because exploitation requires delivering a serialized PHP payload over HTTP, the highest-fidelity detections live in web server access logs and WAF telemetry. Look for PHP serialization signatures (O:, a:, s: type markers with braces) inside request URIs or POST bodies directed at WordPress endpoints.

---
title: PHP Serialized Object in WordPress HTTP Request
description: Detects PHP object serialization signatures in HTTP requests targeting WordPress endpoints, consistent with CVE-2026-19658 PHP Object Injection attempts against the Give Tributes plugin.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-19658
  - https://attack.mitre.org/techniques/T1190/
author: Security Arsenal
date: 2026/04/06
id: 6b2c8f41-1e7a-4d9b-a3c2-9f5e7d1a4b08
status: experimental
tags:
  - attack.initial_access
  - attack.t1190
logsource:
  category: webserver
  product: linux
detection:
  selection_uri:
    cs-uri-query|contains:
      - 'O:%22'
      - 'O:+'
      - 'O:2%3A'
      - 'a%3A1%3A%7B'
  selection_plugin_path:
    cs-uri-stem|contains:
      - '/wp-admin/admin-ajax.php'
      - '/wp-json/'
      - '/wp-content/plugins/give-tributes/'
  condition: selection_uri and selection_plugin_path
falsepositives:
  - Legitimate plugins passing serialized data in query strings (rare but possible)
level: high
---
title: Give Tributes Plugin Endpoint Access on Vulnerable Sites
description: Identifies inbound requests referencing the Give Tributes plugin path, useful for exposure scoping and retro-hunting during CVE-2026-19658 triage.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-19658
author: Security Arsenal
date: 2026/04/06
id: 3d9a1f27-8c44-4b6e-92a1-7e5d2c8f3a19
status: experimental
tags:
  - attack.reconnaissance
  - attack.t1190
logsource:
  category: webserver
  product: linux
detection:
  selection:
    cs-uri-stem|contains:
      - '/wp-content/plugins/give-tributes/'
      - 'give-tributes'
  filter_known_assets:
    cs-uri-stem|endswith:
      - '.css'
      - '.js'
      - '.png'
      - '.svg'
  condition: selection and not filter_known_assets
falsepositives:
  - Legitimate front-end plugin functionality
level: medium

// Hunt for PHP Object Injection payloads targeting WordPress (CVE-2026-19658)
// Works against IIS logs ingested via W3CIISLog or firewall/WAF data in CommonSecurityLog
let serializedPatterns = dynamic(["O:%22", "O:+", "O:2%3A", "a%3A1%3A%7B", "O:8:\\""]);
CommonSecurityLog
| where TimeGenerated > ago(14d)
| where RequestURL has_any (serializedPatterns)
   or (RequestURL has "admin-ajax.php" and RequestURL has "O:")
| where RequestURL has "give-tributes" or RequestURL has "admin-ajax.php" or RequestURL has "wp-json"
| summarize Requests=count(), DistinctSources=dcount(SourceIP), FirstSeen=min(TimeGenerated), LastSeen=max(TimeGenerated)
  by SourceIP, RequestURL, RequestMethod
| order by Requests desc;

-- Velociraptor artifact: identify Give Tributes plugin installs and their version on web servers
-- Run against WordPress hosts to scope CVE-2026-19658 exposure
SELECT FullPath, Mtime,
       read_file(filename=FullPath, length=4096) AS HeaderSnippet
FROM glob(globs='/**/wp-content/plugins/give-tributes/readme.txt',
          root='/var/www')
WHERE HeaderSnippet =~ 'Stable tag'

Remediation Script

Run this on your WordPress hosts to enumerate vulnerable Give Tributes installs and confirm remediation status. It checks the plugin's declared version in its main file and readme, and uses WP-CLI where available.

#!/bin/bash
# CVE-2026-19658 - Give Tributes PHP Object Injection exposure check
# Run as a user with read access to WordPress document roots

VULN_MAX="2.3.1"
FOUND=0

version_lte() {
  [ "$1" = "$(echo -e "$1\n$2" | sort -V | head -n1)" ]
}

for DOCROOT in /var/www /srv/www /home/*/public_html; do
  for PLUGIN_DIR in "$DOCROOT"/*/wp-content/plugins/give-tributes "$DOCROOT"/wp-content/plugins/give-tributes; do
    [ -d "$PLUGIN_DIR" ] || continue
    FOUND=1
    echo "[!] Give Tributes found: $PLUGIN_DIR"

    VER=$(grep -m1 -i "Stable tag" "$PLUGIN_DIR/readme.txt" 2>/dev/null | awk '{print $NF}')
    [ -z "$VER" ] && VER=$(grep -m1 -i "Version:" "$PLUGIN_DIR"/give-tributes.php 2>/dev/null | awk '{print $NF}')
    echo "    Detected version: ${VER:-UNKNOWN}"

    if [ -n "$VER" ] && version_lte "$VER" "$VULN_MAX"; then
      echo "    STATUS: VULNERABLE (<= $VULN_MAX) — update or deactivate immediately"
      WP_DIR=$(dirname "$(dirname "$(dirname "$PLUGIN_DIR")")")
      if command -v wp >/dev/null 2>&1; then
        sudo -u www-data wp --path="$WP_DIR" plugin is-active give-tributes 2>/dev/null \
          && echo "    Plugin is ACTIVE"
      fi
    else
      echo "    STATUS: version above $VULN_MAX or undetermined — verify against vendor advisory"
    fi
  done
done

[ "$FOUND" -eq 0 ] && echo "[+] No Give Tributes installs found in scanned docroots."

# If vulnerable and no patch is deployed, deactivate as a stopgap:
# sudo -u www-data wp --path=/var/www/html plugin deactivate give-tributes

Remediation

1. Patch immediately. Update Give Tributes to a version above 2.3.1 the moment the vendor release is available. Check wp-admin → Plugins or run wp plugin update give-tributes via WP-CLI. Monitor the plugin's WordPress.org page and the vendor changelog for the fixed release.
2. If you cannot patch, deactivate. PHP Object Injection with a network-unauthenticated vector is not a "wait for the next maintenance window" bug. wp plugin deactivate give-tributes removes the attack surface until a fixed release lands.
3. Audit for POP chain exposure. Inventory every installed plugin and theme. The vulnerability's real-world impact is gated by whether a usable POP chain exists elsewhere in your stack — remove abandoned, unmaintained, or unnecessary plugins and themes to shrink that chain surface. Any plugin not updated in 12+ months should be treated as suspect.
4. Hunt retroactively. Run the KQL query and Sigma rules above against at least the last 14–30 days of web logs. Serialized payloads in request parameters aimed at WordPress endpoints are not normal traffic — any hit warrants host-level review for dropped files in uploads/, modified theme files, and unexpected admin accounts (wp user list --role=administrator).
5. Add WAF coverage. Deploy or enable a managed rule blocking PHP serialization signatures (O:, a:{, s: with object metadata) in request bodies and query strings to WordPress paths. Most commercial WordPress WAFs ship virtual patches for disclosed object-injection CVEs within days.
6. Harden the blast radius. Ensure the web server user cannot write to plugin/theme directories outside of update workflows (DISALLOW_FILE_EDIT and ideally DISALLOW_FILE_MODS in wp-config.php with updates handled via deployment pipeline), and enforce least-privilege database credentials so a compromised www-data session cannot drop tables.

Do not deprioritize this because exploitation is currently theoretical. Unauthenticated CVSS 9.8 WordPress plugin flaws with public technical detail are exactly the class that mass-scanning botnets fold into their kits first.

Related Resources

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