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.

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.005 (40.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-15718: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

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.