CVE-2026-48542: Krayin CRM Stored XSS Vulnerability

CVE-2026-48542 Overview

CVE-2026-48542 is a stored client-side template injection vulnerability in Krayin CRM through version 2.2.6. The flaw resides in the product name field, which fails to sanitize Vue.js template expressions before rendering. Authenticated attackers can inject double-brace template syntax that reaches the Vue template compiler. The compiler evaluates attacker-supplied expressions, allowing prototype chain traversal to the Function constructor. This enables arbitrary JavaScript execution in the application origin for every user who views the poisoned product record. The issue is classified under CWE-79: Improper Neutralization of Input During Web Page Generation.

Critical Impact

Any authenticated user who can create or edit products can plant persistent JavaScript payloads that execute in the browsers of all users who view the affected product.

Affected Products

• Krayin CRM versions up to and including 2.2.6
• Deployments using the vulnerable Vue.js client-side template rendering for product records
• Multi-tenant Krayin CRM instances where low-privileged users can create product entries

Discovery Timeline

• 2026-09-24 - CVE-2026-48542 published to NVD
• 2026-09-29 - Last updated in NVD database

Technical Details for CVE-2026-48542

Vulnerability Analysis

The vulnerability stems from Krayin CRM passing user-supplied product name content directly into a Vue.js template context. Vue's template compiler interprets double-brace expressions as JavaScript to evaluate rather than literal text. When an attacker stores a product name containing {{ ... }} syntax, the compiler evaluates the enclosed expression at render time.

Because the expression executes within the page's origin, it inherits the victim's session cookies, CSRF tokens, and application privileges. Each user who navigates to a view listing the poisoned product triggers execution. This persistence transforms a single injected payload into a repeatable attack against every CRM user, including administrators.

Root Cause

The root cause is a missing distinction between data binding and template compilation. The product name field is treated as a template fragment rather than untrusted data interpolated through safe binding directives such as v-text or textContent assignment. Server-side output encoding is likewise absent, so the stored payload survives into the rendered DOM intact.

Attack Vector

An authenticated attacker edits or creates a product and sets the name to a Vue expression that walks the JavaScript prototype chain to retrieve the Function constructor. The constructed function body contains the attacker's JavaScript. When another user loads a page that renders the product name through Vue, the compiler evaluates the expression and executes the payload. Typical post-exploitation actions include session token exfiltration, forced CRM record modifications, and lateral movement to administrative accounts. See the VulnCheck advisory and the CVE disclosure repository for proof-of-concept details.

Detection Methods for CVE-2026-48542

Indicators of Compromise

• Product records whose name field contains double-brace sequences such as {{ and }}, or references to constructor, prototype, or Function.
• Browser console errors referencing Vue template compilation on product listing or detail pages.
• Outbound HTTP requests from CRM user browsers to unfamiliar domains shortly after loading product views.
• Unexpected session cookie or local storage access patterns originating from the CRM origin.

Detection Strategies

• Query the Krayin CRM database for product names matching regex patterns like \{\{.*\}\} to surface stored payloads.
• Review application access logs for product create and update requests from low-privilege accounts containing template delimiter characters.
• Deploy a Content Security Policy report-only header to surface inline script evaluation attempts triggered by injected expressions.

Monitoring Recommendations

• Monitor web proxy and endpoint telemetry for anomalous beacons from browser sessions interacting with the Krayin CRM origin.
• Alert on authenticated API calls that modify product records with payload lengths or character sets inconsistent with legitimate catalog data.
• Track administrator session activity for unexpected privilege actions following product page visits.

How to Mitigate CVE-2026-48542

Immediate Actions Required

• Audit all product records for stored Vue template syntax and remove or sanitize affected entries.
• Restrict product creation and editing permissions to trusted roles until a fixed version is deployed.
• Rotate session tokens and administrator credentials if evidence of payload execution is found.
• Deploy a strict Content Security Policy that disallows inline script evaluation on CRM pages.

Patch Information

No vendor patch is referenced in the published advisory at the time of writing. Monitor the Krayin CRM GitHub repository and the VulnCheck advisory for release notes addressing CVE-2026-48542. Upgrade past version 2.2.6 as soon as a fixed release becomes available.

Workarounds

• Replace Vue template interpolation with the v-text directive or equivalent safe-binding mechanism for all user-controlled fields.
• Apply server-side input validation that rejects or escapes {{ and }} sequences in product metadata fields.
• Enforce a Content Security Policy header such as Content-Security-Policy: script-src 'self'; object-src 'none' to reduce the impact of successful injection.
• Limit product management privileges to a minimal set of vetted CRM operators.

# Example nginx configuration adding a restrictive Content Security Policy
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'none'" always;