CVE•Published 2026-03-24•Modified 2026-07-15•0 articles on news•5 live references•NVD data

CVE-2026-4684Mozilla · Firefox

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

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

EPSS percentile

Exploit Prediction Scoring System · top 73% of all CVEs

Weaknesses (CWE)

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')CWE-416Use After Free CWE-364Signal Handler Race Condition

Description

Race condition, use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Timeline

Published 2026-03-24

Modified 2026-07-15

External references

NVD MITRE Exploit-DB GitHub PoC 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-2026-4684

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-2026-4684