CVE•Published 2026-03-24•Modified 2026-06-30•1 article on news•6 live references•NVD data

CVE-2026-4700Mozilla · Firefox

Vulnerability data via NVD (ingested)

CVSS v3.1

9.8

CRITICAL

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

EPSS percentile

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Weaknesses (CWE)

CWE-288Authentication Bypass Using an Alternate Path or Channel CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Description

Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Timeline

Published 2026-03-24

Modified 2026-06-30

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-4700

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Mozilla Firefox"

All exposed Mozilla Firefox instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Firefox"

HTTP body or banner mentions "Firefox" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-4700