CVE-2026-19988 in SEO Tools Extension
Summary
by MITRE • 08/17/2026
A vulnerability was detected in Alaev SEO Tools Extension up to 1.0.10 on Chrome. This impacts the function addDiv of the file src/popup.html of the component Popup UI. Performing a manipulation results in basic cross site scripting. The attack can be initiated remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 08/17/2026
The Alaev SEO Tools Extension for Google Chrome, specifically versions up to 1.0.10, contains a critical security flaw within its user interface component that allows for remote code execution via cross-site scripting attacks. The vulnerability resides in the addDiv function located in the src/popup.html file of the extension's popup UI module. This architectural placement is significant because browser extensions often operate with elevated privileges compared to standard web pages, meaning any script injection can potentially access sensitive data or perform actions on behalf of the user that would otherwise be restricted by same-origin policies. The flaw stems from insufficient input validation and sanitization when handling dynamic content insertion into the DOM through the addDiv function. When an attacker provides maliciously crafted input that is subsequently rendered without proper encoding, it results in basic cross-site scripting, commonly referred to as stored or reflected XSS depending on how the payload persists within the application state.
From a technical perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation known as Cross-site Scripting. The core issue is that the extension fails to sanitize user-supplied data before inserting it into HTML elements using methods like innerHTML or similar DOM manipulation techniques without escaping special characters such as angle brackets and quotes. This oversight allows an attacker to inject arbitrary JavaScript code that executes in the context of the victim's browser session while interacting with the extension. Since the exploit is publicly available, threat actors can easily leverage this weakness to launch attacks against users who have installed or are using the affected version of the tool. The remote nature of the attack vector means that exploitation does not require physical access or local privilege escalation on the target machine; instead, it relies on social engineering or compromised websites directing victims to trigger the vulnerable function within the extension's interface.
The operational impact of this vulnerability is severe due to the elevated permissions typically granted to browser extensions. An attacker successfully exploiting this flaw can steal session cookies, read sensitive data stored by the extension such as SEO metrics or API keys, and perform actions on behalf of the user across various websites that trust the extension's context. This could lead to account takeover, financial loss if payment information is involved, or further propagation of malware through phishing pages disguised within the trusted environment of the browser toolbar. The fact that the vendor was contacted early regarding this disclosure but failed to respond indicates a lack of active security maintenance and responsible vulnerability management practices by the developer community behind this tool. This silence leaves users exposed without patches or workarounds, increasing the window of exposure for potential exploitation in real-world scenarios where attackers actively scan for known vulnerabilities with public exploits.
Mitigation strategies must focus on immediate remediation since no official patch has been released. Users should uninstall the Alaev SEO Tools Extension immediately to eliminate the attack surface entirely. For organizations managing multiple endpoints, it is advisable to audit installed extensions and remove any that are outdated or from untrusted sources. In environments where removal is not feasible due to legacy dependencies, administrators can consider using browser policies to restrict extension installation or disable specific APIs if supported by the enterprise policy framework. Going forward, developers of browser extensions must adhere to secure coding standards such as OWASP Secure Coding Practices and implement strict input validation on all user-supplied data before DOM manipulation. Utilizing Content Security Policy headers within the extension manifest can also help mitigate the impact of any future XSS vulnerabilities by restricting script execution sources. Regular security audits and penetration testing should be integrated into the development lifecycle to identify and fix such flaws before release, ensuring that extensions do not become vectors for compromising user privacy and system integrity.