CVE-2025-55300Public exploitNetwork attack vector

Command execution via disabled WebSocket origin checks

Published Aug 18, 2025 · Updated Aug 18, 2025

Cross-site WebSocket hijacking in Komari before 1.0.4-fix1 allows remote attackers to execute commands through an administrator's browser. The terminal WebSocket upgrader in api/terminal.go accepts every Origin value, so a third-party page can open the endpoint with ambient session cookies. Exploitation requires a logged-in administrator to visit the malicious page, after which supplied terminal input runs on managed nodes.

CVSS severity8.6
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site WebSocket hijacking in Komari before 1.0.4-fix1 allows remote attackers to execute commands through an administrator's browser. The terminal WebSocket upgrader in api/terminal.go accepts every Origin value, so a third-party page can open the endpoint with ambient session cookies. Exploitation requires a logged-in administrator to visit the malicious page, after which supplied terminal input runs on managed nodes.

The record

CVE
CVE-2025-55300
Published
Aug 18, 2025
Updated
Aug 18, 2025
Vendor
Komari Monitor
Product
Komari
Classifications
CWE-1385, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.0.4-fix1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Komari Monitor · Komariversion=< 1.0.4-fix1

Published CVSS scores

8.6GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1385Missing Origin Validation in WebSockets
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo