CVE-2026-74957: Mozilla Firefox Safe Browsing Mitigation Bypass

HERMES

HERMES THREAT SCORE & DEFENSIVE FILTER EVASION

Target: Mozilla Firefox Safe Browsing Inspection Engine

Confidence: 95%

58 / 100

MEDIUM

Measures real-world operational relevance, exploit weaponization, and active threat posture.

Dimension Breakdown

Exploitability 14 / 20

Threat Activity 11 / 20

Weaponization 12 / 20

Exposure 15 / 20

Prevalence 20 / 20

Impact 11 / 20

Exploit Maturity 11 / 20

Attack Chain Potential 14 / 20

⚖️ Divergence & Operational Rationale

Hermes assesses CVE-2026-74957 at HTS 58 (Medium). Evasion of phishing and malware protection shields users from warnings, facilitating drive-by download and social engineering campaigns.

🕸️ Connected Knowledge Graph & Provenance

CVE-2026-74957: Mozilla Firefox Safe Browsing Mitigation BypassVULNERABILITY

Connected Nodes: 0

Safe Browsing Protection Bypass

CVSS v3.1: 5.3 Medium (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N) / CWE-863: Incorrect Authorization.
Disclosed in Mozilla security updates. An inconsistency in URL canonicalization allows hostile domains to bypass Safe Browsing reputation checks, evading phishing warnings. Fixed in Firefox 154.

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1. Remediation & Hardening

1. Upgrade Firefox: Apply update to Firefox 154 or later.
2. DNS-level Protection: Complement browser protections with secure DNS filtering (DoH / DNS over HTTPS with threat blocking).