CVE-2026-8964
published 2026-05-19CVE-2026-8964: Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCNIHAN
EPSS
0.30%
22.2th percentile
Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 151 | Firefox 151 |
| mozilla | firefox | < 151.0.0 | 151.0.0 |
| mozilla | thunderbird | < Thunderbird 151 | Thunderbird 151 |
| mozilla | thunderbird | < 151.0.0 | 151.0.0 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
vendor_redhat7.5HIGH
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Red Hat
firefox: thunderbird: Spoofing issue in the Popup Blocker component
vendor_redhat·2026-05-19·CVSS 7.5
CVE-2026-8964 [HIGH] CWE-79 firefox: thunderbird: Spoofing issue in the Popup Blocker component
firefox: thunderbird: Spoofing issue in the Popup Blocker component
Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Spoofing issue in the Popup Blocker 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) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not affected
Package: firefox (Red Hat Enterpri
Mozilla
Mozilla Foundation Security Advisory 2026-50: CVE-2026-8964
vendor_mozilla·CVSS 7.5
CVE-2026-8964 [HIGH] Mozilla Foundation Security Advisory 2026-50: CVE-2026-8964
Mozilla Foundation Security Advisory 2026-50
CVE: CVE-2026-8964
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 151
Mozilla
Mozilla Foundation Security Advisory 2026-46: CVE-2026-8964
vendor_mozilla·CVSS 7.5
CVE-2026-8964 [HIGH] Mozilla Foundation Security Advisory 2026-46: CVE-2026-8964
Mozilla Foundation Security Advisory 2026-46
CVE: CVE-2026-8964
Product: Firefox
Impact: high
Fixed in: Firefox 151
VulDB
Mozilla Firefox up to 150 Popup Blocker (EUVD-2026-30915)
vuldb·2026-05-19·CVSS 7.5
CVE-2026-8964 [HIGH] Mozilla Firefox up to 150 Popup Blocker (EUVD-2026-30915)
A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 150. This affects an unknown part of the component Popup Blocker. The manipulation results in an unknown weakness.
This vulnerability is cataloged as CVE-2026-8964. The attack may be launched remotely. There is no exploit available.
You should upgrade the affected component.
GHSA
GHSA-x37c-vm4v-4wvx: Spoofing issue in the Popup Blocker component
ghsa_unreviewed·2026-05-19
CVE-2026-8964 [HIGH] CWE-451 GHSA-x37c-vm4v-4wvx: Spoofing issue in the Popup Blocker component
Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151.
No detection rules found.
No public exploits indexed.
2026-05-19
Published