Vulnerability in Mozilla Firefox

CVE-2026-15718

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.

EPSS: 0.005 (40.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-15718?
CVE-2026-15718 is a medium-severity vulnerability in Mozilla Firefox, classified under Release of Invalid Pointer or Reference. CVSS score: 4.3/10. Published 2026-07-14.
How severe is CVE-2026-15718?
Medium severity. CVSS v3 base score is 4.3 out of 10.
Is CVE-2026-15718 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.