CVE-2026-104286: Fortinet FortiMail Path Traversal Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , the same day the CVE record was published.
- How likely is exploitation in the next 30 days?
- 4.6%
EPSS score, percentile 91.6 of all scored records
- How severe?
- 9.8 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply mitigations in accordance with vendor instructions … Full text
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 8.0.0
- 7.6.0 through 7.6.5
- 7.4.0 through 7.4.6
- 7.2.0 through 7.2.9
- 7.0.0 through 7.0.9
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
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 due date for this action: .
Solution (from the CVE record)
Upgrade to upcoming FortiMail version 8.0.1 or above Upgrade to upcoming FortiMail version 7.6.6 or above Upgrade to upcoming FortiMail version 7.4.8 or above Upgrade to upcoming FortiMail version 7.2.10 or above Upgrade to FortiRecorder version 7.6.1 or above Upgrade to FortiRecorder version 7.2.12 or above Upgrade to upcoming FortiRecorder version 7.0.7 or above Fortinet remediated this issue in FortiMail Cloud version 25.1 (not released) and hence customers do not need to perform any action.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://fortiguard.fortinet.com/psirt/FG-IR-26-175
- 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-2026-104286
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 8.0.0 |
| Affected | 7.6.0 through 7.6.5 |
| Affected | 7.4.0 through 7.4.6 |
| Affected | 7.2.0 through 7.2.9 |
| Affected | 7.0.0 through 7.0.9 |
Versions not listed are: unaffected.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Fortinet FortiMail contains a path traversal and an improper neutralization of NULL byte or NULL character vulnerability that may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2026-104286 to its Known Exploited Vulnerabilities (KEV) catalog on 1 Oct 2026.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 4 Oct 2026.
- The CVE record was published on 1 Oct 2026, the same day it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 4.6% (percentile 91.6), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.8, FortiMail 7.2.0 through 7.2.9 may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
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