DOM Networking Component Privilege Escalation in Firefox

Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

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-2026-74935 is a high-severity privilege escalation vulnerability (CVSS 8.8) affecting the DOM networking component in Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR across multiple versions. This vulnerability allows attackers to escalate privileges through improper access control mechanisms (CWE-269), potentially enabling unauthorized code execution with elevated permissions. The broad version impact across Firefox ESR releases (115.39, 140.14, 153.1) and Thunderbird variants indicates this affects millions of users across enterprise and consumer deployments, making timely patching critical for organizations relying on these browsers.

Casky's 224 mapped security skills leverage Claude AI's extended reasoning to detect the privilege escalation attack patterns underlying TA0004 (Privilege Escalation). Practitioners using Casky would identify detection signals including: suspicious DOM API calls attempting to bypass sandboxing boundaries, network component interactions that circumvent security contexts, and process elevation requests from browser renderer processes. The platform's MITRE ATT&CK correlation reveals defenders should monitor for techniques such as exploiting browser vulnerabilities to gain elevated access, detecting when web content gains system-level permissions it shouldn't possess, and identifying process behavior anomalies in browser child processes that indicate successful privilege escalation. Security teams would see findings highlighting abnormal capability grants to unprivileged contexts and authentication/authorization failures within the DOM networking layer.

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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-2026-74935.

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-2026-74935

Casky has 224 skills that investigate the attack patterns behind CVE-2026-74935. Run one and get CVSS-scored findings in 3 minutes.

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