Unrestricted File Upload and XSS in Hotel Booking Plugin

The VikBooking Hotel Booking Engine & PMS WordPress plugin before 1.8.15 does not restrict the type of files unauthenticated visitors may attach to its live chat, nor sanitize their contents, allowing them to store active content which is executed in the context of an administrator viewing the conversation.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

CVE-2026-85127 is a critical file upload vulnerability in the VikBooking Hotel Booking Engine & PMS WordPress plugin that allows unauthenticated attackers to upload arbitrary files through the live chat feature without validation. The vulnerability chains two severe issues: the absence of file type restrictions and failure to sanitize file contents, enabling attackers to upload files containing malicious scripts that execute with administrator privileges. This affects any WordPress installation running the vulnerable plugin version, with particular risk to hospitality businesses relying on this booking system, as attackers gain direct access to administrative sessions viewing chat conversations.

Casky's 323 matched skills leverage Claude's extended reasoning to detect the attack patterns mapped to MITRE ATT&CK techniques TA0001 (Initial Access) and TA0043 (Reconnaissance). Practitioners using Casky would identify suspicious file upload requests to the live chat endpoint lacking MIME type validation, coupled with cross-site scripting (CWE-79) payloads in uploaded file contents. The platform's security skills would flag the absence of input validation controls, detect execution context escalation when administrator browsers process uploaded files, and recognize the reconnaissance phase where attackers probe chat functionality without authentication. Real-world findings would surface unauthenticated POST requests to chat upload handlers, suspicious file extensions paired with executable content, and abnormal script execution traces in administrator browser contexts—enabling rapid threat detection and plugin patching before compromise.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-85127.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-85127

Casky has 323 skills that investigate the attack patterns behind CVE-2026-85127. Run one and get CVSS-scored findings in 3 minutes.

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