Vulnerability · Published Jul 14, 2026 · Assigned by mozilla

CVE-2026-15718Invalid pointer in the JavaScript: WebAssembly 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 25% 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)4.3Medium
Exploit odds (30 days)0.3%top 74.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC

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 140.13, and Thunderbird 140.13.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10firefox140.13.0-1.el10_2ALSA-2026:47101
AlmaLinux:8firefox140.13.0-1.el8_10.alma.1ALSA-2026:47105
AlmaLinux:9firefox140.13.0-1.el9_8.alma.1ALSA-2026:47104
AlmaLinux:9firefox-x11140.13.0-1.el9_8.alma.1ALSA-2026:47104
AlmaLinux:10thunderbird140.13.0-1.el10_2.alma.1ALSA-2026:49621
AlmaLinux:8thunderbird140.13.0-1.el8_10.alma.1ALSA-2026:49922
AlmaLinux:9thunderbird140.13.0-1.el9_8.alma.1ALSA-2026:49921
Debian:12firefox-esr140.13.0esr-1~deb12u1DEBIAN-CVE-2026-15718
Debian:13firefox-esr140.13.0esr-1~deb13u1DEBIAN-CVE-2026-15718
Debian:14firefox-esr140.13.0esr-1DEBIAN-CVE-2026-15718
Debian:12thunderbird1:140.13.0esr-2~deb12u1DEBIAN-CVE-2026-15718
Debian:13thunderbird1:140.13.0esr-2~deb13u1DEBIAN-CVE-2026-15718
Debian:14thunderbird1:140.13.0esr-1DEBIAN-CVE-2026-15718
Rocky Linux:10firefox0:140.13.0-1.el10_2RLSA-2026:47101
Rocky Linux:8firefox0:140.13.0-1.el8_10RLSA-2026:47105
Rocky Linux:9firefox0:140.13.0-1.el9_8RLSA-2026:47104
Rocky Linux:10thunderbird0:140.13.0-1.el10_2RLSA-2026:49621
Rocky Linux:8thunderbird0:140.13.0-1.el8_10RLSA-2026:49922
Rocky Linux:9thunderbird0:140.13.0-1.el9_8RLSA-2026:49921
Ubuntu:22.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-15718
Ubuntu:24.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-15718
Ubuntu:24.04:LTSmozjs115no fix listedUBUNTU-CVE-2026-15718
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2026-15718
Ubuntu:22.04:LTSmozjs91no fix listedUBUNTU-CVE-2026-15718
Ubuntu:22.04:LTSthunderbirdno fix listedUBUNTU-CVE-2026-15718

Affected products (as reported)

VendorProductVersions
Mozilla Firefox see references
Mozilla Thunderbird see references

Weakness: CWE-763 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

References