Is Firefox affected by CVE-2026-4700?

CVE-2026-4700 presents critical security risk rated CVSS 9.8. Successful exploitation could critically impact the confidentiality, integrity, and availability of affected systems. Organizations should apply vendor updates immediately when available and implement compensating controls in the interim.

CVE-2026-4700

Q: How to fix CVE-2026-4700?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Monitor vendor channels for patch availability.

EUVD-2026-14817 CRITICAL

2026-03-24 mozilla

GHSA-4pf4-jp4v-4g5c

9.8

CVSS 3.1

CVSS Vector

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch Released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 24, 2026 - 12:45 vuln.today

EUVD ID Assigned

Mar 24, 2026 - 12:45 euvd

EUVD-2026-14817

CVE Published

Mar 24, 2026 - 12:30 nvd

CRITICAL 9.8

Description

Mitigation bypass in the Networking: HTTP component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.

Analysis

This vulnerability is a mitigation bypass in Firefox's HTTP networking component that allows attackers to circumvent existing security controls. Firefox versions below 149 and Firefox ESR versions below 140.9 are affected, enabling attackers to bypass authentication or other HTTP-level protections. …

Remediation

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Monitor vendor channels for patch availability.

Analysis

Detailed AI-generated intelligence summary covering attack vector, impact assessment, affected versions, remediation steps, and indicators of compromise.

POChttps://••••••••••.com/exploit

PATCHhttps://••••••••••.com/patch

ADVISORYhttps://••••••••••.com/advisory

Full analysis requires sign-in

Get intelligence summaries, risk assessment, exploit details, threat intel, and remediation guidance.

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +0.0

CVSS: +49

POC: 0

Vendor Status

Debian

firefox

Release	Status	Fixed Version	Urgency
sid	vulnerable	148.0.2-1	-
(unstable)	fixed	(unfixed)	-

firefox-esr

Release	Status	Fixed Version	Urgency
bullseye	vulnerable	115.14.0esr-1~deb11u1	-
bullseye (security)	vulnerable	140.8.0esr-1~deb11u1	-
bookworm	vulnerable	128.14.0esr-1~deb12u1	-
bookworm (security)	vulnerable	140.8.0esr-1~deb12u1	-
trixie (security), trixie	vulnerable	140.8.0esr-1~deb13u1	-
forky, sid	vulnerable	140.8.0esr-1	-
(unstable)	fixed	(unfixed)	-

CVE-2026-4700 vulnerability details – vuln.today

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CVE-2026-4700

CVSS Vector

Lifecycle Timeline

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Description

Analysis

Remediation

Analysis

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Priority Score

Vendor Status

Debian

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CVE-2026-4700

CVSS Vector

Lifecycle Timeline

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Description

Analysis

Remediation

Full analysis requires sign-in

Priority Score

Vendor Status

Debian

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External POC / Exploit Code