Unauthenticated privilege escalation via JRPC path traversal
Published Apr 14, 2026 · Updated Apr 14, 2026
Path traversal in Fortinet FortiSandbox and FortiSandbox Cloud allows remote attackers to escalate privileges via crafted HTTP requests. The JRPC API accepts ../ sequences in the session path and uses them to resolve requests outside the intended session directory, bypassing authentication. No credentials or user interaction are required; exploitation grants privileged access, and observed requests exposed configuration and device details.
Summary
What happened
Path traversal in Fortinet FortiSandbox and FortiSandbox Cloud allows remote attackers to escalate privileges via crafted HTTP requests. The JRPC API accepts ../ sequences in the session path and uses them to resolve requests outside the intended session directory, bypassing authentication. No credentials or user interaction are required; exploitation grants privileged access, and observed requests exposed configuration and device details.
The record
- CVE
- CVE-2026-39813
- Published
- Apr 14, 2026
- Updated
- Apr 14, 2026
- Vendor
- Fortinet
- Product
- FortiSandbox Cloud
- Classifications
- CWE-24, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 14, 2026CVE publishedPublication date reported by the CVE source.
- Apr 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=23.4
- Affected versionversion=24.1
- Affected versionversion=5.0.4 <=5.0.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- JSON-RPC session traversal status requestproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Open-source reporting of FortiSandbox exploitationreported exploitation
Technologies
Your stack
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Your stack
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