Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-12378 – PHP Object Injection / RCE – Appointment Booking Calendar Plugin and Scheduling …

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-12378 is a PHP Object Injection vulnerability affecting the Appointment Booking Calendar Plugin and Scheduling Plugin for WordPress (by codepeople), in all versions through 1.1.28. The flaw arises from the plugin passing user-supplied data to a PHP deserialization function without any validation, allowing unauthenticated, network-based attackers to inject arbitrary PHP objects. Where a suitable gadget chain is available on the target site, this vulnerability can be leveraged to achieve Remote Code Execution (RCE). It carries a CVSS v3.1 base score of 8.1 (High).

Technical details

  • Root cause: The plugin fails to validate or sanitize data before passing it to PHP’s unserialize() function, enabling deserialization of attacker-controlled input.
  • Trigger conditions: The vulnerability is reachable by an unauthenticated attacker over the network; no account, login session, or user interaction is required. Achieving RCE additionally requires a suitable PHP gadget chain to be present on the target WordPress installation (e.g., from another installed plugin or theme).
  • Attack vector: Network (HTTP/HTTPS). WordPress plugins are served on internet-facing sites, making affected installations directly reachable from the internet.
  • Impact: Successful injection of a PHP object with an available gadget chain can result in full remote code execution on the host, leading to complete confidentiality, integrity, and availability compromise of the affected server.

Affected software

  • Appointment Booking Calendar Plugin and Scheduling Plugin (WordPress plugin, author: codepeople) — all versions through 1.1.28

Severity

  • CVSS v3.1 Base Score: 8.1 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Mitigation and recommended actions

  • Immediate – Update: Update the plugin to the latest available version (1.4.04, published June 30, 2026) via the WordPress plugin dashboard. Versions beyond 1.1.28 are not listed as affected.
  • If immediate update is not possible: Consider temporarily deactivating the plugin to eliminate the attack surface until the update can be applied.
  • Defense in depth: Review all other installed plugins and themes for known gadget chains that could be chained with this vulnerability to achieve RCE; reduce the installed plugin surface where possible.

IONIX Status

The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge