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, Fort

Q: How do I fix CVE-2025-53844?

fortios: upgrade to 7.2.12, 7.4.9, 7.6.4. Exact commands for each OS are on this page.

Q: Is CVE-2025-53844 being exploited?

CVE-2025-53844 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-53844 affect?

CVE-2025-53844 affects fortios. Severity is high (CVSS 8.8). 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.

This month

HIGH 8.8UPGRADE

CVE-2025-53844 is a high-severity flaw (CVSS 8.8) affecting fortios. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-05-12
Last modified	2026-10-07

Publisher (CNA): Fortinet, Inc. · Vendor: fortinet

Last updated 2026-10-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-12 18:16 UTCPublished CVE record published
2026-10-07 09:10 UTCUpdated Record last modified

fortinet fortios UPGRADE

Affected: >= 7.2.0 and < 7.2.12 · >= 7.4.0 and < 7.4.9 · >= 7.6.0 and < 7.6.4

Fixed in: 7.2.12, 7.4.9, 7.6.4

Safe to downgrade to: a release before 7.2.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-53844?

fortios: upgrade to 7.2.12, 7.4.9, 7.6.4. Exact commands for each OS are on this page.

Is CVE-2025-53844 being exploited?

CVE-2025-53844 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-53844 affect?

CVE-2025-53844 affects fortios. Severity is high (CVSS 8.8). 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.

How urgent is CVE-2025-53844?

Priority 42/100. High severity

Software pages

Fortinet FortiOS vulnerabilities · Fortinet vulnerabilities

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References

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