How to fix EUVD-2025-18542?

Within 24 hours: Inventory all systems running Nasa Core versions through 6.3.2 and assess exposure; implement Web Application Firewall (WAF) rules to block XSS payloads and validate all user inputs. Within 7 days: Disable Nasa Core if not business-critical; migrate to an alternative theme or apply input sanitization patches if available from community sources; conduct user awareness training on phishing/social engineering. Within 30 days: Upgrade to Nasa Core 6.3.3 or later when vendor patch releases; perform security regression testing; implement Content Security Policy (CSP) headers; establish continuous monitoring for exploitation attempts.

Is NasaTheme Nasa Core affected by EUVD-2025-18542?

A reflected cross-site scripting (XSS) vulnerability in NasaTheme Nasa Core (versions through 6.3.2) allows attackers to inject malicious scripts that execute in users' browsers, potentially compromising user sessions, credentials, and sensitive data.

NasaTheme Nasa Core EUVD-2025-18542

| CVE-2025-39508 HIGH

Cross-site Scripting (XSS) (CWE-79)

2025-06-17 [email protected]

XSS

7.1

CVSS 3.1

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 14, 2026 - 22:15 vuln.today

EUVD ID Assigned

Mar 14, 2026 - 22:15 euvd

EUVD-2025-18542

CVE Published

Jun 17, 2025 - 15:15 nvd

HIGH 7.1

DescriptionNVD

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in NasaTheme Nasa Core allows Reflected XSS. This issue affects Nasa Core: from n/a through 6.3.2.

AnalysisAI

Reflected Cross-Site Scripting (XSS) vulnerability in NasaTheme Nasa Core versions up to 6.3.2 that allows unauthenticated attackers to inject arbitrary JavaScript code into web pages viewed by other users. The vulnerability affects the Nasa Core component through improper input neutralization during web page generation, enabling attackers to steal session cookies, perform actions on behalf of users, or distribute malware. With a CVSS score of 7.1 and low attack complexity, this vulnerability poses a moderate-to-high risk to affected installations, particularly if the affected theme is actively deployed in production environments.

Technical ContextAI

This vulnerability is rooted in CWE-79 (Improper Neutralization of Input During Web Page Generation - Classic XSS), a fundamental web application security flaw where user-supplied input is not properly sanitized or encoded before being rendered in HTML/JavaScript context. NasaTheme Nasa Core, a WordPress theme component, fails to implement adequate input validation and output encoding mechanisms when processing HTTP parameters or form inputs. The reflected nature of this XSS means the malicious payload is contained within the request itself (typically a URL parameter) and is immediately reflected in the response without server-side persistence. Affected versions include Nasa Core from an unspecified baseline through version 6.3.2, suggesting the vulnerability may have existed across multiple releases. The CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C vector indicates the attack requires no privileges and low complexity, but does require user interaction (clicking a malicious link), with cross-site scope impact.

RemediationAI

Immediate actions: (1) Update NasaTheme Nasa Core to a version newer than 6.3.2 if available; verify with the vendor whether 6.3.3+ or later contains a fix. (2) If no patched version is available, disable or remove the Nasa Core theme component until a fix is released. (3) Implement Web Application Firewall (WAF) rules to detect and block common XSS payloads in reflected parameters. (4) Apply output encoding at the template/rendering layer: HTML-encode all user input before rendering in HTML context, JavaScript-encode when inserting into script blocks, and URL-encode when placing in URL attributes. (5) Implement Content Security Policy (CSP) headers with strict script-src directives to mitigate XSS impact even if injection occurs. (6) Apply input validation: whitelist acceptable characters and reject or sanitize suspicious patterns. (7) Contact NasaTheme support directly for patch timeline and availability. (8) Conduct a security audit of custom theme modifications to ensure they don't introduce similar vulnerabilities. No specific patch version number is provided in available data; vendor confirmation is required.

EUVD-2025-18542 vulnerability details – vuln.today

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