CVE-2025-64155
published 2026-01-13CVE-2025-64155: An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0…
PriorityP194critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
42.65%
98.6th percentile
An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.1.0 through 7.1.8, FortiSIEM 7.0.0 through 7.0.4, FortiSIEM 6.7.0 through 6.7.10 may allow an attacker to execute unauthorized code or commands via crafted TCP requests.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| fortinet | fortinet | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | — | — |
| fortinet | fortisiem | >= 6.7.0 < 7.1.9 | 7.1.9 |
| fortinet | fortisiem | >= 7.2.0 < 7.2.7 | 7.2.7 |
| fortinet | fortisiem | >= 7.3.0 < 7.3.5 | 7.3.5 |
| fortinet | fortisiem | 7.3.0 – 7.3.4 | — |
Detection & IOCsextracted from sources · hover to see the quote
snort
alert tcp any any -> $HOME_NET any (msg:"ET EXPLOIT Fortinet FortiSIEM phMonitor Unauthenticated Argument Injection (CVE-2025-64155)"; flow:established,to_server; content:"|9c 00 00 00|"; startswith; content:"|6f 42 1e 40 00 00 00 00|"; distance:4; within:8; content:"|3c|client_type|3e|javaTransportClient"; fast_pattern; content:"|3c|cluster_url|3e|"; pcre:"/^[^\x3c]*?\x20\x2d{1,2}\w+/R"; reference:url,horizon3.ai/attack-research/disclosures/cve-2025-64155-three-years-of-remotely-rooting-the-fortinet-fortisiem/; reference:cve,2025-64155; classtype:attempted-user; sid:2066746; rev:1; metadata:affected_product FortiSIEM, attack_target Server, tls_state TLSDecrypt, created_at 2026_01_14, cve CVE_2025_64155, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2026_01_14, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)bytes
|9c 00 00 00|
bytes
|6f 42 1e 40 00 00 00 00|
- →Search phMonitor message logs for PHL_ERROR entries containing payload URLs and target file paths, indicating exploitation attempts. ↗
- →Monitor for unexpected writes to /opt/charting/redishb.sh, which is the target file overwritten by the PoC exploit to achieve root code execution. ↗
- →Detect TCP traffic to port 7900 (phMonitor service) containing the javaTransportClient client_type field combined with a cluster_url value containing argument injection patterns (e.g., space followed by one or two dashes and a word character).
- →The phMonitor service exposes dozens of command handlers that can be invoked remotely without authentication; any unauthenticated TCP connection to port 7900 should be treated as suspicious. ↗
- →This service (phMonitor) has been the entry point for multiple FortiSIEM vulnerabilities; correlate with prior exploitation patterns for CVE-2023-34992 and CVE-2024-23108 on the same port. ↗
- ·The vulnerability does NOT affect FortiSIEM 7.5 or FortiSIEM Cloud deployments. ↗
- ·The Snort/ET rule requires TLS decryption to be effective, as indicated by the tls_state:TLSDecrypt and deployment:SSLDecrypt metadata.
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vulncheck9.8CRITICAL
CVEs like this are exactly what “Exploited This Week” covers.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Fortinet
Unauthenticated remote command injection
vendor_fortinet·2026-01-13·CVSS 9.8
CVE-2025-64155 [CRITICAL] CWE-78 Unauthenticated remote command injection
FG-IR-25-772: Unauthenticated remote command injection
An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.1.0 through 7.1.8, FortiSIEM 7.0.0 through 7.0.4, FortiSIEM 6.7.0 through 6.7.10 may allow an attacker to execute unauthorized code or commands via crafted TCP requests.
CVEs: CVE-2025-64155
CWEs: CWE-78
CVSS: 9.8 (critical)
Affected products: FortiSIEM, Fortinet
GHSA
GHSA-gvhh-fvm4-vqqj: An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7
ghsa_unreviewed·2026-01-13
CVE-2025-64155 [CRITICAL] CWE-78 GHSA-gvhh-fvm4-vqqj: An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7
An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.1.0 through 7.1.8, FortiSIEM 7.0.0 through 7.0.4, FortiSIEM 6.7.0 through 6.7.10 may allow an attacker to execute unauthorized code or commands via crafted TCP requests.
VulnCheck
Fortinet FortiSIEM Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
vulncheck·2025·CVSS 9.8
CVE-2025-64155 [CRITICAL] Fortinet FortiSIEM Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Fortinet FortiSIEM Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.1.0 through 7.1.8, FortiSIEM 7.0.0 through 7.0.4, FortiSIEM 6.7.0 through 6.7.10 may allow an attacker to execute unauthorized code or commands via crafted TCP requests.
Affected: Fortinet FortiSIEM
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://x.com/DefusedCyber/status/2011825776744595960
Exploit PoC: https://vulncheck.com/xdb/bd906a05caa9; https://vulncheck.
Suricata
ET EXPLOIT Fortinet FortiSIEM phMonitor Unauthenticated Argument Injection (CVE-2025-64155)
suricata·2026-01-14·CVSS 9.8
CVE-2025-64155 [CRITICAL] ET EXPLOIT Fortinet FortiSIEM phMonitor Unauthenticated Argument Injection (CVE-2025-64155)
ET EXPLOIT Fortinet FortiSIEM phMonitor Unauthenticated Argument Injection (CVE-2025-64155)
Rule: alert tcp any any -> $HOME_NET any (msg:"ET EXPLOIT Fortinet FortiSIEM phMonitor Unauthenticated Argument Injection (CVE-2025-64155)"; flow:established,to_server; content:"|9c 00 00 00|"; startswith; content:"|6f 42 1e 40 00 00 00 00|"; distance:4; within:8; content:"|3c|client_type|3e|javaTransportClient"; fast_pattern; content:"|3c|cluster_url|3e|"; pcre:"/^[^\x3c]*?\x20\x2d{1,2}\w+/R"; reference:url,horizon3.ai/attack-research/disclosures/cve-2025-64155-three-years-of-remotely-rooting-the-fortinet-fortisiem/; reference:cve,2025-64155; classtype:attempted-user; sid:2066746; rev:1; metadata:affected_product FortiSIEM, attack_target Server, tls_state TLSDecrypt, created_at 2026_01_14, cve CVE
No public exploits indexed.
Tenable
CVE-2026-35616: Fortinet FortiClientEMS improper access control vulnerability exploited in the wild
blogs_tenable·2026-04-06·CVSS 9.8
[CRITICAL] CVE-2026-35616: Fortinet FortiClientEMS improper access control vulnerability exploited in the wild
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Bleepingcomputer
Hackers now exploiting critical Fortinet FortiSIEM flaw in attacks
blogs_bleepingcomputer·2026-01-16·CVSS 9.8
CVE-2025-64155 [CRITICAL] Hackers now exploiting critical Fortinet FortiSIEM flaw in attacks
## Hackers now exploiting critical Fortinet FortiSIEM flaw in attacks
## Sergiu Gatlan
A critical Fortinet FortiSIEM vulnerability with publicly available proof-of-concept exploit code is now being abused in attacks.
According to security researcher Zach Hanley at penetration testing company Horizon3.ai, who reported the vulnerability ( CVE-2025-64155 ), it is a combination of two issues that allow arbitrary writes with admin permissions and privilege escalation to root access.
"An improper neutralization of special elements used in an OS command ('OS Command Injection') vulnerability [CWE-78] in FortiSIEM may allow an unauthenticated attacker to execute unauthorized code or commands via crafted TCP requests," Fortinet explained on Tuesday, when it released security updates to patch th
Tenable
CVE-2025-64155 PoC released Command Injection Vulnerability
blogs_tenable·2026-01-14·CVSS 9.8
[CRITICAL] CVE-2025-64155 PoC released Command Injection Vulnerability
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Bleepingcomputer
Exploit code public for critical FortiSIEM command injection flaw
blogs_bleepingcomputer·2026-01-14·CVSS 10.0
CVE-2025-64155 [CRITICAL] Exploit code public for critical FortiSIEM command injection flaw
## Exploit code public for critical FortiSIEM command injection flaw
## Bill Toulas
Technical details and a public exploit have been published for a critical vulnerability affecting Fortinet's Security Information and Event Management (SIEM) solution that could be leveraged by a remote, unauthenticated attacker to execute commands or code.
The vulnerability is tracked as CVE-2025-64155, and is a combination of two issues that permit arbitrary write with admin permissions and privilege escalation to root access.
Researchers at penetration testing company Horizon3.ai reported the security issue in mid-August 2025, but it was only fixed on January 13, 2026.
Fortinet describes the CVE-2025-64155 vulnerability as "an improper neutralization of special elements used in an OS command vulnera
Wiz
CVE-2026-25972 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.9
CVE-2026-25972 [CRITICAL] CVE-2026-25972 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-25972 :
FortiSIEM vulnerability analysis and mitigation
An improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4 may allow a remote unauthenticated attacker to provide arbitrary data enabling a social engineering attack via spoofed URL parameters.
Source : NVD
## 6.1
Score
Published March 10, 2026
Severity MEDIUM
CNA Score 4.3
Affected Technologies
FortiSIEM
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 14.4
Exploitation Probability (EPSS) N/A
Affected packages and libraries
cpe:2.3:a:fortinet:fortisiem
Sources
Linux Severity MEDIUM Has Fix Added at: Mar 10, 2026
Wiz
CVE-2025-64155 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.9
CVE-2025-64155 [CRITICAL] CVE-2025-64155 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2025-64155 :
FortiSIEM vulnerability analysis and mitigation
An improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.1.0 through 7.1.8, FortiSIEM 7.0.0 through 7.0.4, FortiSIEM 6.7.0 through 6.7.10 may allow an attacker to execute unauthorized code or commands via crafted TCP requests.
Source : NVD
## 9.8
Score
Published January 13, 2026
Severity CRITICAL
CNA Score 9.8
Affected Technologies
FortiSIEM
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 23.2
Exploitation Probability (EPSS) 0.1
Affected packages and libraries
cpe:2.3:a:fortinet:fortisiem
Sour
2026-01-13
Published
Exploited in the wild