Vulnerability · Published Oct 13, 2026 · Assigned by mozilla
CVE-2026-109715Incorrect boundary conditions in the JavaScript Engine component
High 8.1
In plain English
A high-severity memory corruption 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 24% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.3%top 75.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC
Official description
Incorrect boundary conditions in the JavaScript Engine component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 153.5.0-1.el10_2 | ALSA-2026:89758 |
| AlmaLinux:8 | firefox | 153.5.0-1.el8_10 | ALSA-2026:89756 |
| AlmaLinux:9 | firefox | 153.5.0-1.el9_8 | ALSA-2026:89757 |
| AlmaLinux:9 | firefox-x11 | 153.5.0-1.el9_8 | ALSA-2026:89757 |
| AlmaLinux:9 | thunderbird | 153.5.0-1.el9_8.alma.1 | ALSA-2026:93443 |
| Debian:12 | firefox-esr | 153.5.0esr-1~deb12u1 | DEBIAN-CVE-2026-109715 |
| Debian:13 | firefox-esr | 153.5.0esr-1~deb13u1 | DEBIAN-CVE-2026-109715 |
| Debian:14 | firefox-esr | 153.5.0esr-1 | DEBIAN-CVE-2026-109715 |
| Debian:12 | thunderbird | 1:153.5.1esr-1~deb12u1 | DEBIAN-CVE-2026-109715 |
| Debian:13 | thunderbird | 1:153.5.1esr-1~deb13u1 | DEBIAN-CVE-2026-109715 |
| Debian:14 | thunderbird | 1:153.5.0esr-1 | DEBIAN-CVE-2026-109715 |
| Rocky Linux:10 | firefox | 0:153.5.0-1.el10_2 | RLSA-2026:89758 |
| Rocky Linux:8 | firefox | 0:153.5.0-1.el8_10 | RLSA-2026:89756 |
| Rocky Linux:9 | firefox | 0:153.5.0-1.el9_8 | RLSA-2026:89757 |
| Rocky Linux:9 | thunderbird | 0:153.5.0-1.el9_8 | RLSA-2026:93443 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-109715 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-109715 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-109715 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-109715 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-109715 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-109715 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2073267
- https://www.mozilla.org/security/advisories/mfsa2026-106/
- https://www.mozilla.org/security/advisories/mfsa2026-107/
- https://www.mozilla.org/security/advisories/mfsa2026-108/
- https://www.mozilla.org/security/advisories/mfsa2026-109/
- https://www.mozilla.org/security/advisories/mfsa2026-110/