DOM Navigation Component Privilege Escalation in Firefox

Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Casky was already ahead

This CVE exploits attack patterns that Casky's 224matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

CVE-2026-16371 is a critical privilege escalation vulnerability (CVSS 9.8) in the DOM Navigation component affecting Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR. This vulnerability exploits improper handling of permissions and access controls (CWE-269) within the browser's navigation stack, allowing attackers to escalate privileges beyond their intended scope. The flaw impacts all users of affected versions, particularly those who interact with untrusted web content or malicious sites that could trigger the vulnerability through crafted navigation sequences.

Casky's 224 matched skills detect this vulnerability by mapping to MITRE ATT&CK technique TA0004 (Privilege Escalation), using Claude AI's extended reasoning to identify attack patterns across multiple detection vectors. Practitioners using Casky would observe findings related to abnormal DOM manipulation, suspicious navigation stack manipulation, unexpected permission grants, and process context changes that deviate from legitimate browser behavior. The platform's security skills enable detection of reconnaissance activities probing navigation boundaries, exploitation attempts leveraging DOM methods, and post-exploitation privilege persistence—giving practitioners granular visibility into how attackers chain DOM navigation abuse with privilege escalation tactics to achieve persistent code execution.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

224 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-16371.

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

Access with Stolen Session Cookie

penetration testing · medium

Run

MITRE ATT&CK Techniques

TA0004

Investigate the attack patterns behind CVE-2026-16371

Casky has 224 skills that investigate the attack patterns behind CVE-2026-16371. Run one and get CVSS-scored findings in 3 minutes.

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