Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-27960

opencti Privilege escalation and unauthenticated access

OpenCTI-Platform / opencti · >= 6.6.0, < 6.9.13

View live feed Monitor via API Watch CVE-2026-27960
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
2.0%
First observed
20 Sep 2026
Last observed
23 Sep 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-27960 is an unauthenticated vulnerability affecting OpenCTI-Platform opencti. OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. In versions 6.6.0 through...

Is it exploited?

Yes. Previdian sensors observed exploitation attempts with confirmed confidence. Also confirmed by third-party sources.

Who is affected?

OpenCTI-Platform / opencti >= 6.6.0, < 6.9.13.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. In versions 6.6.0 through 6.9.12, there is a privilege escalation vulnerability that can be exploited by unauthenticated attackers to query the API as any existing user, including the default admin account.

This issue has been fixed in version 6.9.13. As a workaround, the default admin can be disabled using the `APP__ADMIN__EXTERNALLY_MANAGED` configuration.

OpenCTI-Platform Affected
opencti
>= 6.6.0, < 6.9.13
Published
05 May 2026
Exploitation Reported
20 Sep 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nuclei_scanner

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

Previdian

Recorded 20 Sep 2026

Previdian independently recorded this as exploited after first seeing it in honeypot sensors.

Active exploitation observed

Previdian sensor

First observed 20 Sep 2026

Previdian first observed exploitation attempts targeting this vulnerability in our honeypot sensors.

Proof of concept available

Pruva

Recorded 30 Jul 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

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Source Added
Previdian First 2026-09-21 08:06 UTC
The Shadowserver 2026-09-22 00:00 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Previdian sensors recorded exploitation attempts targeting this vulnerability. The cards and chart show volume, unique attackers, and daily activity.

2

Attempts observed

2

Unique attacker IPs

2

Attacker countries

CH · YE

2

Sensors observed

CVE-2026-27960 exploitation attempts over the last 7 days

Daily events observed by Previdian sensors

Updated 24 Sep 2026

0
0
1
0
0
1
0
18 Sep 19 Sep 20 Sep 21 Sep 22 Sep 23 Sep 24 Sep

First observed 20 Sep 2026 · Last observed 23 Sep 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

Request telemetry access

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
1
2
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-27960.yaml 16 Sep 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

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

EPSS

2.0%

Weaknesses

Improper Authentication CWE-287

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

OpenCTI authentication bypass via user impersonation

pruva · Created 2026-07-30 07:51:02 UTC

Severity: CRITICAL | CVE: CVE-2026-27960 | Package: opencti

OpenCTI authentication bypass via user impersonation

pruva · Created 2026-07-30 07:51:02 UTC

Severity: CRITICAL | CVE: CVE-2026-27960 | Package: opencti

OpenCTI < 6.9.13 - Authentication Bypass via User Impersonation

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. 13:18 UTC

    Indicators of compromise added (2)

    Indicators of compromise recorded

  3. 13:18 UTC

    Observed by Previdian sensors

    Evidence-backed exploitation signal

  4. 04:30 UTC

    Nuclei template available

    Scanner coverage available

  5. 07:51 UTC

    Public PoC available

    Public proof-of-concept code published

  6. 18:35 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 03:24 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-27960

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-27960",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.01995,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 2, "sensors": 2 }
}