CVSS 3.1
9.6 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HCVE-2026-121529 fortinet: Origin Validation Error
Critical (9.6) in fortinet. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
On this page
A origin validation error vulnerability in Fortinet FortiClientMac 7.4.0 through 7.4.7, FortiClientWindows 7.4.0 through 7.4.7, FortiClientWindows 7.2.0 through 7.2.14, FortiClientWindowsPAM 7.4.7, FortiClientWindowsPAM 7.2.14 may allow an unauthorized remote attacker to execute unauthorized code or commands. Successful exploitation requires interaction with the victim.
Severity
- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 12th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: total, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-346 Origin Validation Error
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Modified
- Assigned by
- fortinet (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
Ask an AI about this CVE
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Explain CVE-2026-121529 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-121529?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-121529?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-121529 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Fortinet FortiClientMac | from 7.4.0 through 7.4.7 |
| Fortinet FortiClientWindows | from 7.4.0 through 7.4.7 |
| Fortinet FortiClientWindows | from 7.2.0 through 7.2.14 |
| Fortinet FortiClientWindowsPAM | 7.4.7 |
| Fortinet FortiClientWindowsPAM | 7.2.14 |
GitHub PoC (unverified)
Repositories on GitHub named after this CVE. Nobody has checked them and they are not scanned: some hold a working proof of concept, some nothing useful, and some malware made to look like one. Read the code before you run any of it.
- ashrafzaryouh/CVE-2026-121529 1 star, created
CVE-2026-121529 - Ghost-Bx1/cve-2026-121529-forticlient-cors-rce 0 stars, Python, created
CVE-2026-121529 - FortiClient CORS RCE (CVSS 9.1) - googlesky/CVE-2026-121529 0 stars, Python, created
Containerised PoC for CVE-2026-121529 (FG-IR-26-194): a FortiClient local API origin validation error (CWE-346) that lets a malicious web p…
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-346 (16).