CVE-2026-100765
published 2026-09-29CVE-2026-100765: Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.
PriorityP347high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.29%
20.3th percentile
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 157 | Firefox 157 |
| mozilla | firefox | < 153.4.0 | 153.4.0 |
| mozilla | firefox | >= 154.0.0 < 157.0.0 | 157.0.0 |
| mozilla | firefox_esr | < Firefox ESR 153.4 | Firefox ESR 153.4 |
| mozilla | thunderbird | < Thunderbird 157 | Thunderbird 157 |
| mozilla | thunderbird | < Thunderbird 153.4 | Thunderbird 153.4 |
| mozilla | thunderbird | < 153.4.0 | 153.4.0 |
| mozilla | thunderbird | >= 154.0 < 157.0 | 157.0 |
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Mozilla
Mozilla Foundation Security Advisory 2026-101: CVE-2026-100765
vendor_mozilla·CVSS 8.8
CVE-2026-100765 [HIGH] Mozilla Foundation Security Advisory 2026-101: CVE-2026-100765
Mozilla Foundation Security Advisory 2026-101
CVE: CVE-2026-100765
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 157
Mozilla
Mozilla Foundation Security Advisory 2026-100: CVE-2026-100765
vendor_mozilla·CVSS 8.8
CVE-2026-100765 [HIGH] Mozilla Foundation Security Advisory 2026-100: CVE-2026-100765
Mozilla Foundation Security Advisory 2026-100
CVE: CVE-2026-100765
Product: Firefox ESR
Impact: low
Fixed in: Firefox ESR 153.4
Mozilla
Mozilla Foundation Security Advisory 2026-103: CVE-2026-100765
vendor_mozilla·CVSS 8.8
CVE-2026-100765 [HIGH] Mozilla Foundation Security Advisory 2026-103: CVE-2026-100765
Mozilla Foundation Security Advisory 2026-103
CVE: CVE-2026-100765
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 153.4
Mozilla
Mozilla Foundation Security Advisory 2026-97: CVE-2026-100765
vendor_mozilla·CVSS 8.8
CVE-2026-100765 [HIGH] Mozilla Foundation Security Advisory 2026-97: CVE-2026-100765
Mozilla Foundation Security Advisory 2026-97
CVE: CVE-2026-100765
Product: Firefox
Impact: low
Fixed in: Firefox 157
VulDB
Mozilla Firefox up to 153.3/156 WebAssembly use after free (WID-SEC-2026-3654)
vuldb·2026-10-03·CVSS 8.8
CVE-2026-100765 [HIGH] Mozilla Firefox up to 153.3/156 WebAssembly use after free (WID-SEC-2026-3654)
A vulnerability classified as critical has been found in Mozilla Firefox up to 153.3/156. Affected is an unknown function of the component WebAssembly. Performing a manipulation results in use after free.
This vulnerability was named CVE-2026-100765. The attack may be initiated remotely. There is no available exploit.
It is recommended to upgrade the affected component.
GHSA
Use-after-free in the JavaScript: WebAssembly component.
ghsa_unreviewed·2026-09-29
CVE-2026-100765 [HIGH] CWE-416 Use-after-free in the JavaScript: WebAssembly component.
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-09-29
Published