Unauthenticated Authentication bypass and Privilege escalation in FortiSandbox

unknownCVE-2026-39813

CVSSv3 Score: 9.1 A Path Traversal vulnerability [CWE-24] in FortiSandbox JRPC API may allow an unauthenticated attacker to bypass authentication via specially crafted HTTP requests. Revised on 2026-04-14 00:00:00

CSIRTS triage

vendor: Fortinet product: FortiSandbox Authentication bypass Privilege escalation

What: An unauthenticated attacker can bypass authentication and escalate privileges via crafted HTTP requests.
Who is affected: Deployments of FortiSandbox.
Urgency: This critical vulnerability requires immediate remediation to prevent unauthorized access and privilege escalation.
Action: Update FortiSandbox to the latest version to mitigate this vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Fortinet FortiGuard PSIRT (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-04-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://fortiguard.fortinet.com/psirt/FG-IR-26-112

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Elevated exploitation riskCVE-2026-3981323.1% 30-day exploitation probability — well above the norm. Schedule remediation this cycle. Riskier than 98% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-39813	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

criticalexploitedFortinet security advisory (AV26-351) – Update 2cccs