Evidence used
- CISA confirms exploitation in the wild.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 76.11% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-25089High confidence
Fortinet FortiSandbox OS Command Injection Vulnerability
Fortinet · FortiSandbox
Official source article: Fortinet FG-IR-26-141 ↗. Check the applicable product and release in the original source.
9.1CriticalCVSS 3.1
Patch now
Patch availableCISA confirms exploitation in the wild and lists 2026-07-19 as the remediation due date.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Fortinet FortiSandbox and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
CISA confirms exploitation in the wild and lists 2026-07-19 as the remediation due date.
Patch available01
What, why and how
Fortinet FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS contain an OS command injection vulnerability that allows an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests.
What
Fortinet FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS contain an OS command injection vulnerability that allows an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Fortinet FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS contain an OS command injection vulnerability that allows an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation Confirmed in the wild
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-07-16.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-78 ↗
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:CCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Fixed
- Upgrade to upcoming FortiSandbox version 5.2.0 or above
- Upgrade to FortiSandbox version 5.0.6 or above
- Upgrade to FortiSandbox version 4.4.9 or above
- Upgrade to upcoming FortiSandbox PaaS version 5.2.0 or above
- Upgrade to FortiSandbox PaaS version 5.0.6 or above
- Fortinet remediated this issue in FortiSandbox Cloud version 5.2.0 (not released) and hence customers do not need to perform any action.
- Fortinet remediated this issue in FortiSandbox Cloud version 5.0.6 (not released) and hence customers do not need to perform any action.
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
Official vendor articles1 stored document
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- PSIRT | FortiGuard Labs →Original publisher ↗Searchable text snapshot · Captured 28 Sep 2026PSIRT Second-Order OS Command Injection via JSON Input on start vnc feature Summary An improper neutralization of special elements used in an OS command vulnerability [CWE-78] in FortiSandbox, FortiSandbox Cloud and FortiSandbox PaaS WEB UI may allow an unauthenticated attacker to execute unauthorized commands via spec
04
Evidence and provenance
Published 9 Jun 2026 · Last source change 17 Jul 2026, 03:56 UTC · CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-35443
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.BlackTree editorial ↗
- Before
- no BlackTree article
- After
- 1 BlackTree article
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: fortiguard.fortinet.com/FG-IR-26-141.psirt@fortinet.com ↗
- Before
- vendor advisory: fortiguard.fortinet.com/FG-IR-26-141
- After
- remediation: fortiguard.fortinet.com/FG-IR-26-141 · vendor advisory: fortiguard.fortinet.com/FG-IR-26-141
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- 5.0.0 ≤ 5.0.5; 4.4.0 ≤ 4.4.8; 4.2.1 ≤ 4.2.8; 5.0.4 ≤ 5.0.5 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- FortiSandbox: 5.0.0 ≤ 5.0.5, 4.4.0 ≤ 4.4.8, 4.2.1 ≤ 4.2.8; FortiSandbox Cloud: 5.0.4 ≤ 5.0.5; FortiSandbox PaaS: 5.0.4 ≤ 5.0.5 · Fixed: Upgrade to upcoming FortiSandbox version 5.2.0 or above; Upgrade to FortiSandbox version 5.0.6 or above; Upgrade to FortiSandbox version 4.4.9 or above; Upgrade to upcoming FortiSandbox PaaS version 5.2.0 or above; Upgrade to FortiSandbox PaaS version 5.0.6 or above; Fortinet remediated this issue in FortiSandbox Cloud version 5.2.0 (not released) and hence customers do not need to perform any action.; Fortinet remediated this issue in FortiSandbox Cloud version 5.0.6 (not released) and hence customers do not need to perform any action.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.psirt@fortinet.com ↗
- Before
- Awaiting fix
- After
- Patch available
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.