CVE-2025-55054: Cross-Site Scripting (XSS) Vulnerability

CVE-2025-55054 Overview

CVE-2025-55054 is a Cross-Site Scripting (XSS) vulnerability categorized under [CWE-79] Improper Neutralization of Input During Web Page Generation. The flaw allows attackers to inject malicious script content into web pages generated by the affected application. Successful exploitation requires user interaction, such as clicking a crafted link, and can lead to session compromise or unauthorized actions within the victim's browser context. The vulnerability was published to the National Vulnerability Database (NVD) on September 9, 2025. Details about the affected vendor and product have not been disclosed in the public advisory referenced by the Israeli Government CVE Advisories.

Critical Impact
Attackers can execute arbitrary scripts in a victim's browser, enabling session theft, credential harvesting, and unauthorized actions on the affected web application.

Affected Products

Specific affected products have not been disclosed in the public advisory
Refer to the Israeli Government CVE Advisories for vendor-specific guidance
Web application component vulnerable to reflected or stored XSS input

Discovery Timeline

2025-09-09 - CVE-2025-55054 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-55054

Vulnerability Analysis

CVE-2025-55054 stems from improper neutralization of user-supplied input during web page generation. The application incorporates attacker-controlled data into HTML, JavaScript, or attribute contexts without sufficient encoding or sanitization. When a victim loads the affected page, the browser executes the injected script under the origin of the vulnerable application.

The attack requires network access to the target application and user interaction to trigger the payload. The scope is marked as changed, meaning script execution can affect resources beyond the vulnerable component, including cross-origin data accessible through the trusted domain. Confidentiality and integrity impacts are limited but meaningful — an attacker can read data visible to the victim's session and perform actions on their behalf.

Root Cause

The root cause is missing or incomplete output encoding when rendering user-controllable input into an HTML response. Common patterns include reflecting query parameters directly into the DOM, storing untrusted values without HTML entity encoding, or using unsafe sinks such as innerHTML and document.write with unvalidated data. Without contextual escaping for HTML, attribute, JavaScript, and URL contexts, injected markup is parsed and executed by the victim's browser.

Attack Vector

An attacker crafts a URL or form submission containing script payloads and delivers it through phishing, malicious links, or third-party content. When the victim visits the crafted URL or interacts with the poisoned resource, the vulnerable page renders the payload. The script then runs in the security context of the target origin, allowing cookie theft, DOM manipulation, keystroke capture, or forced navigation. Because privileges are not required, unauthenticated attackers can target any user of the application.

See the Israeli Government CVE Advisories for additional technical details.

Detection Methods for CVE-2025-55054

Indicators of Compromise

Web server access logs containing script tags, javascript: URIs, or event handler attributes such as onerror= and onload= in query parameters or POST bodies
Outbound requests from user browsers to unfamiliar domains shortly after visiting the affected application
Unexpected session token usage from geographies or user agents inconsistent with the legitimate user
Content Security Policy (CSP) violation reports referencing inline script execution on affected pages

Detection Strategies

Deploy web application firewall (WAF) rules that flag common XSS payload patterns in HTTP request parameters
Enable CSP with report-uri or report-to directives to capture attempted script injections
Perform authenticated dynamic application security testing (DAST) scans against exposed endpoints to identify reflected and stored XSS sinks

Monitoring Recommendations

Correlate anomalous browser-side telemetry with server-side request logs to identify successful payload delivery
Alert on user sessions exhibiting rapid, scripted actions immediately after inbound referrals from external domains
Track EPSS scoring changes for CVE-2025-55054 and re-prioritize remediation if exploitation likelihood increases

How to Mitigate CVE-2025-55054

Immediate Actions Required

Consult the Israeli Government CVE Advisories to identify the affected product and apply vendor-supplied patches
Enforce a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins
Audit application input handling code for unsafe sinks such as innerHTML, document.write, and unencoded template variables

Patch Information

Vendor-specific patch information is not included in the current NVD entry. Administrators should monitor the referenced advisory source for updates and apply fixes as they become available. Until patches are confirmed, prioritize compensating controls such as WAF rules and CSP hardening.

Workarounds

Apply server-side input validation with allowlists for expected character sets on all user-supplied parameters
Use context-aware output encoding libraries when rendering untrusted data into HTML, attribute, JavaScript, or URL contexts
Set the HttpOnly and Secure flags on session cookies to reduce the impact of successful script execution
Educate users to avoid clicking untrusted links referencing the affected application until patches are confirmed

bash

# Example Content Security Policy header to mitigate XSS impact
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'none'; report-uri /csp-report