CVE-2026-25089
CVE-2026-25089 is a security flaw in Fortinet FortiSandbox, Fortinet’s business security equipment. Attackers can run commands on Fortinet FortiSandbox from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 16 Jul 2026.[1]
Fortinet FortiSandbox is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fortinet has published a fix or advice.
Description
CISA calls it an OS command injection in Fortinet FortiSandbox. In its words: “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.”[1]
The CVE record adds: “A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8, FortiSandbox 4.2 all versions, FortiSandbox Cloud 5.0.4 through 5.0.5, FortiSandbox PaaS 5.0.4 through 5.0.5 may allow an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests”[2]
The underlying weakness is OS command injection (CWE-78), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Fortinet’s advisory has them[3]. CISA names the product as Fortinet FortiSandbox.
Most families won’t have Fortinet FortiSandbox; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 16 Jul 2026, 37 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 19 Jul 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 76%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Fortinet has published a fix or advice.[3] CISA’s required action: “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).”[1]
- Check whether you use it.Fortinet FortiSandbox is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 19 Jul 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 76%.[4] |
See also
Other Fortinet FortiSandbox flaws
- CVE-2026-39808: OS command injection ·
Other Fortinet flaws
- CVE-2025-61624, Fortinet products: path traversal ·
- CVE-2026-104286, Fortinet FortiMail: path traversal ·
- CVE-2025-25249, Fortinet products: heap-based buffer overflow ·
- CVE-2025-68686, Fortinet FortiOS: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-21643, Fortinet FortiClient EMS: SQL injection ·
Other OS command injection flaws
- CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
- CVE-2026-106931, EG Secure Solutions SiteGuard Server Edition: OS command injection ·
- CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
- CVE-2026-49869, Kestra OSS: OSS OS command injection ·
- CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·
Added the same day
- CVE-2026-58644, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-39808, Fortinet FortiSandbox: OS command injection ·
Every Fortinet flaw on CISA’s list · Everything added in July 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Fortinet FortiSandbox OS Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 16 Jul 2026.
- ^ National Institute of Standards and Technology. “CVE-2026-25089 Detail”. National Vulnerability Database, published 9 Jun 2026.
- ^ Fortinet. Advisories and fixes: fortiguard.fortinet.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.761, percentile 99.5, 31 Oct 2026.
- CVE Program. “CVE-2026-25089”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.