Exploited vulnerabilities / CVE-2025-25249
Confirmed exploited · memory corruption · Fortinet Multiple ProductsCVE-2025-25249
Fortinet Multiple Products memory corruption, confirmed exploited in the wild.
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.
| CISA's name for it | Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability |
|---|---|
| Vendor and product | Fortinet · Multiple Products |
| Type | memory corruption · CWE-122, CWE-787 |
| Exploited | Confirmed by CISA listed 9 September 2026 |
| Likelihood | more likely to be exploited than most |
| Deadline | 12 September 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | fortiguard.fortinet.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Update the product (and every browser or app that embeds it) to the fixed version.
Make sure automatic updates are on and actually applied; restart where the update needs it.
Watch endpoints for crashes and unusual child processes from the affected software.
| CISA's 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. |
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Know before someone else finds it
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CVE-2025-25249 in short
Is CVE-2025-25249 being exploited?
Yes. CISA added CVE-2025-25249 to its Known Exploited Vulnerabilities catalogue on 9 September 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2025-25249?
US federal agencies must remediate it by 12 September 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2025-25249 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 3.7%, the 90th percentile of every CVE it scores.
How do I fix CVE-2025-25249?
Update the product (and every browser or app that embeds it) to the fixed version. Make sure automatic updates are on and actually applied; restart where the update needs it. Watch endpoints for crashes and unusual child processes from the affected software.
Other Fortinet vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2025-61624 | Multiple Products | path traversal | 16 October 2026 |
| CVE-2026-104286 | FortiMail | path traversal | 1 October 2026 |
| CVE-2025-68686 | FortiOS | exploited vulnerability | 27 July 2026 |
| CVE-2026-25089 | FortiSandbox | command injection | 16 July 2026 |
| CVE-2026-39808 | FortiSandbox | command injection | 16 July 2026 |
| CVE-2026-21643 | FortiClient EMS | SQL injection | 13 April 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.