CVE-2026-6758
Use-after-free in the JavaScript: WebAssembly component
Description
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
INFO
Published Date :
April 21, 2026, 1:16 p.m.
Last Modified :
April 22, 2026, 2:55 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Firefox to version 150 or newer.
Public PoC/Exploit Available at Github
CVE-2026-6758 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-2026-6758.
| URL | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2013619 | Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2026-30/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-33/ | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6758 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-2026-6758
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).
Tracking Vulnerabilities That Appear to be Credited to the Anthropic Research Team
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6758 vulnerability anywhere in the article.
-
CybersecurityNews
Mozilla Patches 423 Firefox 0-Day Vulnerabilities with Claude Mythos and Other AI Models
Mozilla has fixed a total of 423 Firefox security bugs in April 2026 alone, a figure nearly 20 times higher than its monthly average of about 21 bugs throughout 2025, driven by a groundbreaking agenti ... Read more
-
security.nl
Mozilla: Firefox kwetsbaarheden door Claude Mythos van Anthropic ontdekt
Mozilla heeft deze week een nieuwe versie van Firefox uitgebracht waarin 271 kwetsbaarheden zijn verholpen die door een AI-model van Anthropic zijn ontdekt. Het gaat om een vroege versie van Claude My ... Read more
The following table lists the changes that have been made to the
CVE-2026-6758 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.
-
Initial Analysis by [email protected]
Apr. 22, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 150.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* versions up to (excluding) 150.0 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/show_bug.cgi?id=2013619 Types: Permissions Required Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-30/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-33/ Types: Vendor Advisory -
CVE Modified by [email protected]
Apr. 22, 2026
Action Type Old Value New Value Changed Description Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150. Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150. Added Reference https://www.mozilla.org/security/advisories/mfsa2026-33/ -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 21, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-416 -
New CVE Received by [email protected]
Apr. 21, 2026
Action Type Old Value New Value Added Description Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150. Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2013619 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-30/