CVE-2026-8947
published 2026-05-19CVE-2026-8947: Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151…
PriorityP340high7.3CVSS 3.1
AVNACLPRNUINSUCLILAL
EPSS
0.41%
33.5th percentile
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 151 | Firefox 151 |
| mozilla | firefox | < 115.36.0 | 115.36.0 |
| mozilla | firefox | < 151.0.0 | 151.0.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 140.0 < 140.11.0 | 140.11.0 |
| mozilla | firefox_esr | < Firefox ESR 115.36 | Firefox ESR 115.36 |
| mozilla | firefox_esr | < Firefox ESR 140.11 | Firefox ESR 140.11 |
| mozilla | thunderbird | < Thunderbird 140.11 | Thunderbird 140.11 |
| mozilla | thunderbird | < Thunderbird 151 | Thunderbird 151 |
| mozilla | thunderbird | < 140.11 | 140.11 |
| rhel10 | firefox-flatpak | — | — |
CVSS provenance
nvdv3.17.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
vendor_redhat7.3HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Mozilla Firefox up to 115.35/140.10/150 WebIDL use after free (EUVD-2026-30896)
vuldb·2026-05-19·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Firefox up to 115.35/140.10/150 WebIDL use after free (EUVD-2026-30896)
A vulnerability was found in Mozilla Firefox up to 115.35/140.10/150. It has been declared as critical. This vulnerability affects unknown code of the component WebIDL. Such manipulation leads to use after free.
This vulnerability is traded as CVE-2026-8947. The attack may be launched remotely. There is no exploit available.
It is recommended to upgrade the affected component.
GHSA
GHSA-6fhv-h367-4jc4: Use-after-free in the DOM: Bindings (WebIDL) component
ghsa_unreviewed·2026-05-19
CVE-2026-8947 [HIGH] CWE-416 GHSA-6fhv-h367-4jc4: Use-after-free in the DOM: Bindings (WebIDL) component
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, and Firefox ESR 140.11.
Red Hat
firefox: Use-after-free in the DOM: Bindings (WebIDL) component
vendor_redhat·2026-05-19·CVSS 7.3
CVE-2026-8947 [HIGH] CWE-825 firefox: Use-after-free in the DOM: Bindings (WebIDL) component
firefox: Use-after-free in the DOM: Bindings (WebIDL) component
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:
Use-after-free in the DOM: Bindings (WebIDL) component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox (Red Hat Enterprise Linux 7) - Affected
Package: firefox (Red Hat Enterprise Linux 8) - Affected
Package: firefox (Red Hat Enterprise Linux 9) - Affected
Mozilla
Mozilla Foundation Security Advisory 2026-47: CVE-2026-8947
vendor_mozilla·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Foundation Security Advisory 2026-47: CVE-2026-8947
Mozilla Foundation Security Advisory 2026-47
CVE: CVE-2026-8947
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.36
Mozilla
Mozilla Foundation Security Advisory 2026-51: CVE-2026-8947
vendor_mozilla·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Foundation Security Advisory 2026-51: CVE-2026-8947
Mozilla Foundation Security Advisory 2026-51
CVE: CVE-2026-8947
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-48: CVE-2026-8947
vendor_mozilla·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Foundation Security Advisory 2026-48: CVE-2026-8947
Mozilla Foundation Security Advisory 2026-48
CVE: CVE-2026-8947
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.11
Mozilla
Mozilla Foundation Security Advisory 2026-50: CVE-2026-8947
vendor_mozilla·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Foundation Security Advisory 2026-50: CVE-2026-8947
Mozilla Foundation Security Advisory 2026-50
CVE: CVE-2026-8947
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 151
Mozilla
Mozilla Foundation Security Advisory 2026-46: CVE-2026-8947
vendor_mozilla·CVSS 7.3
CVE-2026-8947 [HIGH] Mozilla Foundation Security Advisory 2026-46: CVE-2026-8947
Mozilla Foundation Security Advisory 2026-46
CVE: CVE-2026-8947
Product: Firefox
Impact: high
Fixed in: Firefox 151
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2038439https://www.mozilla.org/security/advisories/mfsa2026-46/https://www.mozilla.org/security/advisories/mfsa2026-47/https://www.mozilla.org/security/advisories/mfsa2026-48/https://www.mozilla.org/security/advisories/mfsa2026-50/https://www.mozilla.org/security/advisories/mfsa2026-51/https://access.redhat.com/errata/RHSA-2026:21378https://access.redhat.com/errata/RHSA-2026:21380https://access.redhat.com/errata/RHSA-2026:21381https://access.redhat.com/errata/RHSA-2026:21382https://access.redhat.com/errata/RHSA-2026:22325https://access.redhat.com/errata/RHSA-2026:22643https://access.redhat.com/errata/RHSA-2026:26174https://access.redhat.com/errata/RHSA-2026:26268https://access.redhat.com/errata/RHSA-2026:26269https://access.redhat.com/errata/RHSA-2026:26270https://access.redhat.com/errata/RHSA-2026:26491https://access.redhat.com/errata/RHSA-2026:26492https://access.redhat.com/errata/RHSA-2026:26493https://access.redhat.com/errata/RHSA-2026:26521https://access.redhat.com/errata/RHSA-2026:26536https://access.redhat.com/errata/RHSA-2026:26539https://access.redhat.com/errata/RHSA-2026:26551https://access.redhat.com/errata/RHSA-2026:26606https://access.redhat.com/errata/RHSA-2026:26629https://access.redhat.com/errata/RHSA-2026:26630https://access.redhat.com/errata/RHSA-2026:27715https://access.redhat.com/security/cve/CVE-2026-8947https://bugzilla.redhat.com/show_bug.cgi?id=2479873https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8947.json
2026-05-19
Published