Vulnerability · Published Jan 13, 2026 · Assigned by mozilla
CVE-2026-0887Clickjacking issue, information disclosure in the PDF Viewer component
Medium 4.3
In plain English
A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.3%top 74.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 140.7.0-1.el10_1 | ALSA-2026:2271 |
| AlmaLinux:8 | firefox | 140.7.0-1.el8_10.alma.1 | ALSA-2026:0667 |
| AlmaLinux:9 | firefox | 140.7.0-1.el9_7.alma.1 | ALSA-2026:0694 |
| AlmaLinux:9 | firefox-x11 | 140.7.0-1.el9_7.alma.1 | ALSA-2026:0694 |
| AlmaLinux:10 | thunderbird | 140.7.0-1.el10_1.alma.1 | ALSA-2026:2286 |
| AlmaLinux:8 | thunderbird | 140.7.0-1.el8_10.alma.1 | ALSA-2026:2220 |
| AlmaLinux:9 | thunderbird | 140.7.0-1.el9_7.alma.1 | ALSA-2026:0924 |
| Debian:12 | firefox-esr | 140.7.0esr-1~deb12u1 | DEBIAN-CVE-2026-0887 |
| Debian:12 | firefox-esr | 140.7.0esr-1~deb12u1 | DSA-6101-1 |
| Debian:13 | firefox-esr | 140.7.0esr-1~deb13u1 | DEBIAN-CVE-2026-0887 |
| Debian:13 | firefox-esr | 140.7.0esr-1~deb13u1 | DSA-6101-1 |
| Debian:14 | firefox-esr | 140.7.0esr-1 | DEBIAN-CVE-2026-0887 |
| Debian:12 | thunderbird | 1:140.7.0esr-1~deb12u1 | DSA-6103-1 |
| Debian:12 | thunderbird | 1:140.7.0esr-1~deb12u1 | DEBIAN-CVE-2026-0887 |
| Debian:13 | thunderbird | 1:140.7.0esr-1~deb13u1 | DSA-6103-1 |
| Debian:13 | thunderbird | 1:140.7.0esr-1~deb13u1 | DEBIAN-CVE-2026-0887 |
| Debian:14 | thunderbird | 1:140.7.0esr-1 | DEBIAN-CVE-2026-0887 |
| Rocky Linux:8 | firefox | 0:140.7.0-1.el8_10 | RLSA-2026:0667 |
| Rocky Linux:9 | firefox | 0:140.7.0-1.el9_7 | RLSA-2026:0694 |
| Rocky Linux:8 | thunderbird | 0:140.7.0-1.el8_10 | RLSA-2026:2220 |
| Rocky Linux:9 | thunderbird | 0:140.7.0-1.el9_7 | RLSA-2026:0924 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-0887 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-0887 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-0887 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-0887 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-0887 |
| Ubuntu:22.04:LTS | thunderbird | 1:140.7.1+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2026-0887 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-497 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N