CVE-2026-48543 Overview
CVE-2026-48543 is a stored client-side template injection vulnerability in Krayin CRM through version 2.2.6. Authenticated attackers can inject Vue.js template expressions into the web form description field. The injected double-brace syntax reaches the Vue template compiler and executes arbitrary JavaScript in the browser of every user who views the affected web form. The flaw is tracked under CWE-79 and allows prototype chain traversal to obtain the Function constructor for arbitrary script execution in the application origin.
Critical Impact
Authenticated attackers can execute arbitrary JavaScript in other users' browsers within the Krayin CRM origin, enabling session abuse, data exfiltration, and account takeover against viewers of a poisoned web form.
Affected Products
- Krayin CRM versions through 2.2.6
- Deployments exposing the web form builder to authenticated users
- Instances rendering web form descriptions through the Vue template compiler
Discovery Timeline
- 2026-09-24 - CVE-2026-48543 published to the National Vulnerability Database
- 2026-09-25 - Last updated in NVD database
Technical Details for CVE-2026-48543
Vulnerability Analysis
The vulnerability resides in how Krayin CRM processes the description field of its web form builder. User-supplied content is passed into a context where the Vue.js template compiler evaluates expressions enclosed in double-brace delimiters. Because the application does not strip or escape template syntax before rendering, any string placed in the description can be treated as executable template code.
An authenticated attacker with permission to create or modify a web form stores a payload containing Vue expressions. When another authenticated user loads the form view, the compiler evaluates the expression against the component context. Through prototype chain traversal, the payload reaches the JavaScript Function constructor and executes arbitrary code within the application origin.
The stored nature of the flaw amplifies impact. Any user who browses the compromised form triggers execution without additional interaction beyond navigating to the page.
Root Cause
The root cause is improper neutralization of input used in a template context, consistent with CWE-79. Krayin CRM sends the raw description field through the Vue template compiler instead of binding it as inert text. The compiler treats {{ expression }} syntax as code, bypassing the standard HTML entity escaping that would ordinarily block script tags.
Attack Vector
Exploitation requires authenticated access with permission to create or edit a web form. The attacker injects a payload that uses property access chains to resolve the Function constructor from a benign prototype reference. The returned constructor is invoked with attacker-supplied JavaScript source, which executes when the Vue runtime renders the form. User interaction is required only to the extent that a victim must load the affected form page. Full technical details and proof-of-concept materials are documented in the VulnCheck Advisory for Krayin CRM and the GitHub CVE Disclosure Repository.
Detection Methods for CVE-2026-48543
Indicators of Compromise
- Web form description fields containing double-brace {{ }} sequences or references to constructor, __proto__, or Function.
- Database records in Krayin web form tables showing template expressions in description columns.
- Browser console errors or unexpected network requests originating from the web form view page.
Detection Strategies
- Query the Krayin CRM web form storage for description fields matching regular expressions such as \{\{.*\}\} or containing JavaScript identifiers like constructor and Function.
- Enable web server access logging and review POST requests to the web form create and update endpoints for suspicious payloads.
- Deploy a web application firewall rule that inspects multipart form submissions for Vue template delimiters in description parameters.
Monitoring Recommendations
- Alert on authenticated users who modify web forms outside expected administrative hours or at unusual frequency.
- Correlate browser-side Content Security Policy violation reports with user sessions viewing web form pages.
- Monitor outbound requests from authenticated sessions for data exfiltration patterns following form page loads.
How to Mitigate CVE-2026-48543
Immediate Actions Required
- Restrict web form creation and edit permissions to a minimal set of trusted administrators until a patch is applied.
- Audit existing web form descriptions for template expressions and remove any suspicious entries.
- Rotate session tokens and credentials for users who may have viewed untrusted web forms.
Patch Information
At the time of publication, no fixed version has been identified in the enriched CVE data. Monitor the VulnCheck Advisory for Krayin CRM and the Krayin CRM project for an official security release. Apply updates as soon as a patched version becomes available.
Workarounds
- Sanitize the web form description field at the application layer to strip or escape {{ and }} sequences before storage or rendering.
- Render description content with v-text or interpolate it as plain text instead of passing it to the Vue template compiler.
- Deploy a strict Content Security Policy that disallows unsafe-eval to block execution via the Function constructor.
# Example Content Security Policy header to block Function constructor execution
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
