CVEs / CVE-2025-25249
CVE-2025-25249: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
- Known exploited in the CISA KEV catalog since 9 Sep 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 3.74% chance of exploitation in the next 30 days, higher than 89% of CVEs (30 Oct 2026)
- Last changed at its sources
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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.
Description
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
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Fortinet FortiSwitchManager | from 7.2.2, up to and including 7.2.5 | — |
| Fortinet FortiOS | from 7.6.0, up to and including 7.6.2 | — |
| Fortinet FortiOS | from 7.4.0, up to and including 7.4.7 | — |
| Fortinet FortiOS | from 7.2.4, up to and including 7.2.11 | — |
| Siemens RUGGEDCOM APE1808 | all versions | — |
Exploitation
| In CISA KEV since | 9 Sep 2026 |
|---|---|
| Due date for US federal agencies | 12 Sep 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-122, CWE-787 |
References
- CVE-2025-25249 on NVD
- CVE-2025-25249 in the CISA KEV catalog
- https://fortiguard.fortinet.com/psirt/FG-IR-25-084 (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://fortiguard.fortinet.com/psirt/FG-IR-25-084 Mitigation, Vendor Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-864900.html Third Party Advisory
- https://socradar.io/blog/cve-2025-25249-pivotc2-fortigate-rat/ Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-25249 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.