Vulnerability · Published Jul 14, 2026 · Assigned by mozilla
CVE-2026-15719Site isolation issue in the DOM: Navigation component
Medium 5.4
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 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 78.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
We are aware that exploit code for this is public however we are not aware of any attacks in the wild abusing this flaw. This vulnerability was fixed in Firefox 152.0.6, Firefox ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 140.13.0-1.el10_2 | ALSA-2026:47101 |
| AlmaLinux:8 | firefox | 140.13.0-1.el8_10.alma.1 | ALSA-2026:47105 |
| AlmaLinux:9 | firefox | 140.13.0-1.el9_8.alma.1 | ALSA-2026:47104 |
| AlmaLinux:9 | firefox-x11 | 140.13.0-1.el9_8.alma.1 | ALSA-2026:47104 |
| AlmaLinux:10 | thunderbird | 140.13.0-1.el10_2.alma.1 | ALSA-2026:49621 |
| AlmaLinux:8 | thunderbird | 140.13.0-1.el8_10.alma.1 | ALSA-2026:49922 |
| AlmaLinux:9 | thunderbird | 140.13.0-1.el9_8.alma.1 | ALSA-2026:49921 |
| Debian:12 | firefox-esr | 140.13.0esr-1~deb12u1 | DEBIAN-CVE-2026-15719 |
| Debian:13 | firefox-esr | 140.13.0esr-1~deb13u1 | DEBIAN-CVE-2026-15719 |
| Debian:14 | firefox-esr | 140.13.0esr-1 | DEBIAN-CVE-2026-15719 |
| Debian:12 | thunderbird | 1:140.13.0esr-2~deb12u1 | DEBIAN-CVE-2026-15719 |
| Debian:13 | thunderbird | 1:140.13.0esr-2~deb13u1 | DEBIAN-CVE-2026-15719 |
| Debian:14 | thunderbird | 1:140.13.0esr-1 | DEBIAN-CVE-2026-15719 |
| Rocky Linux:10 | firefox | 0:140.13.0-1.el10_2 | RLSA-2026:47101 |
| Rocky Linux:8 | firefox | 0:140.13.0-1.el8_10 | RLSA-2026:47105 |
| Rocky Linux:9 | firefox | 0:140.13.0-1.el9_8 | RLSA-2026:47104 |
| Rocky Linux:10 | thunderbird | 0:140.13.0-1.el10_2 | RLSA-2026:49621 |
| Rocky Linux:8 | thunderbird | 0:140.13.0-1.el8_10 | RLSA-2026:49922 |
| Rocky Linux:9 | thunderbird | 0:140.13.0-1.el9_8 | RLSA-2026:49921 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-15719 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-15719 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-15719 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-15719 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-15719 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-15719 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |