Is CVE-2026-39813 actively exploited?

Yes. CVE-2026-39813 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2026-39813 be exploited remotely?

Yes. CVE-2026-39813 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39813?

CVE-2026-39813 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2026-39813

CRITICALCISA KEVIN THE WILD

CVE-2026-39813

CWE-24Published: April 14, 2026· Updated: Apr 20, 2026

9.8

CVSS v3.1

EPSS:0.06%probability of exploitation in 30 daysPercentile:18.1th

Official Description

A path traversal: '../filedir' vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8 may allow attacker to escalation of privilege via <insert attack vector here>

NVD Source

Technical Analysis

CVE-2026-39813 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CISA has added CVE-2026-39813 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Fortinet1 product

fortisandbox

Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

ACTIVE EXPLOITATIONConfirmed exploitation in the wild

Exploit-DB

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

PacketStorm

Security advisories & exploits

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://fortiguard.fortinet.com/psirt/FG-IR-26-112

News & Research Mentioning CVE-2026-39813

Attackers Exploit Three Fortinet FortiSandbox Flaws, One Patched Last Week

The Hacker News· Jun 16, 2026

Bad actors are exploiting multiple security vulnerabilities in Fortinet FortiSandbox, according to threat intelligence firm Defused Cyber. In a post shared on X, the company said it has observed exploitation of CVE-2026-39813, CVE-2026-39808, and CVE-2026-25089 over the past 24 hours. CVE-2026-39813 (CVSS score: 9.1) refers to a path traversal vulnerability in FortiSandbox JRPC API that could [xlite_meta score:59 src:The Hacker News xlite_fp:3d6eed6907e27ebf5a19e46f7d03d3c5e37518d9ef87643dc9f503ad3fd82a66]