CVE-2026-16369CWE-190

CVE-2026-16369

Critical · published July 21, 2026

CVSS v3.1

9.8

EPSS

Percentile

36.9

In the wild

Unconfirmed

What it is

Integer overflow in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

The record

Technical detail

CVSS v3.1: 9.8 · CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0: Not supplied
EPSS: 0.00436 · 36.9th percentile
Weakness: CWE-190 · Integer Overflow or Wraparound
Published: 2026-07-21T17:17Z

Affected products (4)

Product	Versions	Fixed in
mozilla/firefox	< 140.13.0	140.13.0
mozilla/firefox	< 153.0.0	153.0.0
mozilla/thunderbird	< 140.13.0	140.13.0
mozilla/thunderbird	≥ 141.0, < 153.0	153.0

References (5)

https://bugzilla.mozilla.org/show_bug.cgi?id=2051854 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-68/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-70/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-71/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-72/ · [email protected]

EPSS history

Timeline

21 JUL 12:37Z
Integer overflow in the JavaScript: WebAssembly component
cvelistv5