CVE-2025-25249: Fortinet Multiple Products

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

Yes, if you run Fortinet Multiple Products. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-09-09, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-09-12; treat that as the outer limit, not the target.
EPSS 3.8%, percentile 90: FIRST’s model estimates a 3.8% chance of exploitation activity in the next 30 days, higher than 90% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
Editorial verdict: Act now. FortiOS CVE-2025-25249 and CVE-2025-61624 Now Exploited — If you run FortiGates, get to FortiOS 7.4.10+ or 7.6.5+ now and hunt for implants: one bug gives unauthenticated attackers code execution over CAPWAP and is being exploited at scale, and the other turns stolen admin logins into root implants.

What it is

A heap-based buffer overflow 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, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows attacker to execute unauthorized code or commands via specially crafted packets

CISA’s summary

Fortinet FortiOS, FortiSwitchManager, and FortiSASE contain a heap-based buffer overflow vulnerability that allows an attacker to execute unauthorized code or commands via specially crafted packets.

Weakness type: CWE-122, CWE-787.

Product: Fortinet Multiple Products · Assigned by: fortinet · Published: 2026-01-13

Affected and fixed versions

Vendor	Product	Affected versions (per CVE record)
Fortinet	FortiSwitchManager	7.2.2 <= 7.2.5
Fortinet	FortiOS	7.6.0 <= 7.6.2, 7.4.0 <= 7.4.7, 7.2.4 <= 7.2.11

Severity scores

Scored by	CVSS	Score	Vector
fortinet	3.1	7.4 High	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:W/RC:C`

Attack vector: network (remotely reachable)
Attack complexity: high (needs special conditions)
Privileges required: none (no login)
User interaction: none
Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: added 2026-09-09; federal due date 2026-09-12. Known ransomware use: Unknown.
CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA SSVC assessment: exploitation active, automatable no, technical impact total.
FIRST EPSS (model of 2026-10-21): 3.80% probability of exploitation activity in the next 30 days; percentile 90.

Timeline

2026-01-13 — CVE record published by fortinet
2026-01-13 — erroneo.us brief: FortiOS CVE-2025-25249 and CVE-2025-61624 Now Exploited
2026-09-09 — Added to CISA’s Known Exploited Vulnerabilities catalog
2026-09-12 — CISA remediation deadline for US federal agencies
2026-10-15 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Other references from the CVE record and advisory

socradar.io socradar.io
cert-portal.siemens.com cert-portal.siemens.com

All exploited Fortinet vulnerabilities · Today’s Security Digest