CVE-2026-6757

MEDIUM 6.3CVE-2026-6757 · Published 21/04/2026 · updated 26/10/2026

In short

CVE-2026-6757 is a MEDIUM (CVSS 6.3) vulnerability affecting firefox (mozilla), thunderbird (mozilla).
Chance of exploitation in the next 30 days (EPSS): 0.49%, higher than 42.1% of all vulnerabilities.
Fix: update to 140.10.0, 150.0 or later.

Package	Affected versions	Patched versions
firefox mozilla	`< 140.10.0< 150.0`	`140.10.0150.0`
thunderbird mozilla	`≥ 140.0, < 140.10.0`	`140.10.0`

Description

Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

References

bugzilla.mozilla.org/show_bug.cgi · Permissions Required
mozilla.org/security/advisories/mfsa2026-30 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-32 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-33 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-34 · Vendor Advisory

More vulnerabilities in firefox

See all →

Running one of these products? Scan your site to see whether it exposes a vulnerable version.

Scan my site free

Package

Affected versions

Patched versions

firefox

mozilla

< 140.10.0< 150.0

140.10.0150.0

thunderbird

mozilla

≥ 140.0, < 140.10.0

140.10.0

More vulnerabilities in firefox

See all →