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CVE-2026-27728: Hackerbay Oneuptime OS Command Injection (CVSS 9.9)

CVE-2026-27728 is a critical severity os command injection in Hackerbay Oneuptime with a CVSS score of 9.9. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-27728 is a critical severity os command injection in Hackerbay Oneuptime with a CVSS score of 9.9. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
9.9CRITICAL
EPSS probability
2.60%
Higher than 85 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:L)Low complexity
Privileges required (PR:L)Low privileges required
User interaction (UI:N)No user interaction
Scope (S:C)Scope changed: impact spreads beyond the component
Confidentiality (C:H)High confidentiality impact
Integrity (I:H)High integrity impact
Availability (A:H)High availability impact

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

About Hackerbay Oneuptime

CVE-2026-27728 affects Hackerbay Oneuptime, a product from Hackerbay. Before acting, confirm where Hackerbay Oneuptime runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: OneUptime is a solution for monitoring and managing online services. Prior to version 10.0.7, an OS command injection vulnerability in `NetworkPathMonitor.performTraceroute()` allows any authenticated project user to execute arbitrary operating system commands on the Probe server by injecting shell metacharacters into a monitor's destination field. Version 10.0.7 fixes the vulnerability.

The weakness class is OS Command Injection. Untrusted input is passed to the operating system shell, letting an attacker run commands.

Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductHackerbay Oneuptime
Affected versionsOneuptime before 10.0.7
PublishedFeb 25, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAsecurity-advisories@github.com

How to detect it

  • Inventory every instance of Hackerbay Oneuptime and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Hackerbay Oneuptime named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Hackerbay Oneuptime to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-27728 is a critical severity os command injection in Hackerbay Oneuptime with a CVSS score of 9.9. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Related CVEs

CRITICAL9.2
CVE-2026-35053
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OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, the Worker service's ManualAPI exposes workflow execution endpoints (GET /workflow/manual/run/:workflowId and POST /workflow/manual/run/:workflowId) without any authentication middleware. An attacker who can obtain or guess a workflow ID can trigger arbitrary workflow execution with attacker-controlled input data, enabling JavaScript code execution, notification abuse, and data manipulation. This issue has been patched in version 10.0.42.

Apr 2, 2026
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OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, multiple notification API endpoints are registered without authentication middleware, while sibling endpoints in the same codebase correctly use ClusterKeyAuthorization.isAuthorizedServiceMiddleware. These endpoints are externally reachable via the Nginx proxy at /notification/. Combined with a projectId leak from the public Status Page API, an unauthenticated attacker can purchase phone numbers on the victim's Twilio account and delete all existing alerting numbers. This issue has been patched in version 10.0.42.

Apr 2, 2026
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OneUptime is a solution for monitoring and managing online services. Prior to version 10.0.34, the WhatsApp POST webhook handler (/notification/whatsapp/webhook) processes incoming status update events without verifying the Meta/WhatsApp X-Hub-Signature-256 HMAC signature, allowing any unauthenticated attacker to send forged webhook payloads that manipulate notification delivery status records, suppress alerts, and corrupt audit trails. The codebase already implements proper signature verification for Slack webhooks. This issue has been patched in version 10.0.34.

Mar 20, 2026
HIGH7.2
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OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, an unauthenticated path traversal in the /workflow/docs/:componentName endpoint allows reading arbitrary files from the server filesystem. The componentName route parameter is concatenated directly into a file path passed to res.sendFile() in orker/FeatureSet/Workflow/Index.ts with no sanitization or authentication middleware. This vulnerability is fixed in 10.0.21.

Mar 10, 2026
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OneUptime is a solution for monitoring and managing online services. In version 10.0.11 and prior, the WebAuthn authentication implementation does not store the challenge on the server side. Instead, the challenge is returned to the client and accepted back from the client request body during verification. This violates the WebAuthn specification (W3C Web Authentication Level 2, §13.4.3) and allows an attacker who has obtained a valid WebAuthn assertion (e.g., via XSS, MitM, or log exposure) to replay it indefinitely, completely bypassing the second-factor authentication. No known patches are available.

Mar 6, 2026
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WeGIA is a web manager for charitable institutions. Prior to version 3.6.5, a critical Remote Code Execution (RCE) vulnerability exists in the WeGIA application's database restoration functionality. An attacker with administrative access (which can be obtained via the previously reported Authentication Bypass) can execute arbitrary OS commands on the server by uploading a backup file with a specifically crafted filename. Version 3.6.5 fixes the issue.

Feb 27, 2026
All Hackerbay CVEs in 2026
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