CVE-2026-4684
Race condition, use-after-free in the Graphics: WebRender component
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.
INFO
Published Date :
March 24, 2026, 1:16 p.m.
Last Modified :
April 13, 2026, 3:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-4684
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Firefox to the latest version.
- Update Firefox ESR to the latest version.
Public PoC/Exploit Available at Github
CVE-2026-4684 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-4684.
| URL | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2011129 | Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2026-20/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-21/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-22/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-23/ | |
| https://www.mozilla.org/security/advisories/mfsa2026-24/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4684 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-4684
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-4684 vulnerability anywhere in the article.
-
CybersecurityNews
Firefox 149 Released With Patch for 37 Vulnerabilities that Enables Remote Attacks
Mozilla released Firefox 149 on March 24, 2026, delivering one of the largest security advisories in the browser’s recent history, addressing 37 vulnerabilities spanning memory corruption, sandbox esc ... Read more
The following table lists the changes that have been made to the
CVE-2026-4684 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Apr. 13, 2026
Action Type Old Value New Value Changed Description Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. 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. -
CVE Modified by [email protected]
Mar. 24, 2026
Action Type Old Value New Value Changed Description Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. Added Reference https://www.mozilla.org/security/advisories/mfsa2026-23/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-24/ -
Initial Analysis by [email protected]
Mar. 24, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 149.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions up to (excluding) 115.34.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions from (including) 128.0 up to (excluding) 140.9.0 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/show_bug.cgi?id=2011129 Types: Permissions Required Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-20/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-21/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-22/ Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 24, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-362 Added CWE CWE-416 -
New CVE Received by [email protected]
Mar. 24, 2026
Action Type Old Value New Value Added Description Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2011129 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-20/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-21/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-22/