CVE-2026-84138
published 2026-09-01CVE-2026-84138: Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
PriorityP428medium6.5CVSS 3.1
AVNACLPRNUIRSUCNINAH
EPSS
0.37%
29.7th percentile
Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 155 | Firefox 155 |
| mozilla | firefox | < 155.0.0 | 155.0.0 |
| mozilla | thunderbird | < Thunderbird 155 | Thunderbird 155 |
| mozilla | thunderbird | < 155.0 | 155.0 |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
vendor_redhat6.5MEDIUM
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Red Hat
firefox: thunderbird: Denial-of-service in the PDF Viewer component
vendor_redhat·2026-09-01·CVSS 6.5
CVE-2026-84138 [MEDIUM] CWE-835 firefox: thunderbird: Denial-of-service in the PDF Viewer component
firefox: thunderbird: Denial-of-service in the PDF Viewer component
Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Denial-of-service in the PDF Viewer 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 2026-86: CVE-2026-84138
vendor_mozilla
CVE-2026-84138 Mozilla Foundation Security Advisory 2026-86: CVE-2026-84138
Mozilla Foundation Security Advisory 2026-86
CVE: CVE-2026-84138
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 155
Mozilla
Mozilla Foundation Security Advisory 2026-82: CVE-2026-84138
vendor_mozilla
CVE-2026-84138 Mozilla Foundation Security Advisory 2026-82: CVE-2026-84138
Mozilla Foundation Security Advisory 2026-82
CVE: CVE-2026-84138
Product: Firefox
Impact: high
Fixed in: Firefox 155
GHSA
Denial-of-service in the PDF Viewer component.
ghsa_unreviewed·2026-09-01
CVE-2026-84138 Denial-of-service in the PDF Viewer component.
Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155.
No detection rules found.
No public exploits indexed.
2026-09-01
Published