Buffer overflow in Fortinet Fortios

CVE-2025-53844

A out-of-bounds write vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11 allows attacker to execute unauthorized code or commands via specially crafted packets.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (44.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.7% 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-2025-53844: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-53844?
CVE-2025-53844 is a high-severity vulnerability in Fortinet Fortios, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-05-12.
How severe is CVE-2025-53844?
High severity. CVSS v3 base score is 8.8 out of 10.