CVE-2025-25249: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
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
Description quoted from the CVE record (assigned by fortinet, published 2026-01-13).
Weakness: Execute unauthorized code or commands
How it can be exploited
Exploitable over the network with high attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability 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
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2026-09-09
- US federal deadline
- 2026-09-12
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2026-00381, CNNVD-202601-2159, EUVD-2026-2223, GHSA-mj8x-m8f5-x4w8
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Research and write-ups (1)
- Research or write-up: https://arcticwolf.com/resources/blog/cve-2025-25249
Vulnerability databases and vendor advisories (5)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-2223
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-mj8x-m8f5-x4w8
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2025-25249
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-25249
- Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202601-2159
News (1)
10 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.037
some chance of attack soon - VEDAS
- 0.521
some exploit evidence - On CISA KEV
- Yes, since 2026-09-09
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
VEDAS flagged this bug about 7 days before CISA confirmed attacks.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Fortinet FortiSwitchManager | from 7.2.2 up to and including 7.2.5 | Not stated |
| Fortinet FortiOS | from 7.6.0 up to and including 7.6.2 from 7.4.0 up to and including 7.4.7 from 7.2.4 up to and including 7.2.11 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: fortinet fortios, fortinet fortisase, fortinet fortiswitchmanager, fortinet_inc. fortios, fortinet_inc. fortiswitchmanager.
How to fix it
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.
Vendor guidance:
- https://fortiguard.fortinet.com/psirt/FG-IR-25-084
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2025-25249
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Exploits and technical analysis
- https://socradar.io/blog/cve-2025-25249-pivotc2-fortigate-rat/ (third-party-advisory)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-25249 (government-resource)
Other references
- https://fortiguard.fortinet.com/psirt/FG-IR-25-084
- https://cert-portal.siemens.com/productcert/html/ssa-864900.html
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.