CVE-2026-21887
OpenCTI has a Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.7
OpenCTI has a Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
- Record
CVE-2026-21887- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
EUVDEUVD-2026-11599
7.7
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
- Record
EUVD-2026-11599- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-ffm6-vvph-g5f5
7.7
OpenCTI has Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
Summary
The OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs.
This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems.
Impact
OpenCTI’s data ingestion feature can allow an attacker to make the application send HTTP requests to arbitrary internal or external endpoints. This means an attacker could reach internal services that are not exposed publicly, such as Elasticsearch, Redis, or RabbitMQ, and potentially extract sensitive data or manipulate internal components. In cloud environments, the attacker could target metadata services like AWS, Azure, or GCP to obtain credentials and configuration details, which could lead to full compromise of the infrastructure. Even though the SSRF is semi-blind and the attacker may not see the full response, the ability to interact with internal services can enable enumeration, data exfiltration, and in some cases remote code execution if internal APIs expose dangerous functionality.
- Record
GHSA-ffm6-vvph-g5f5- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-20, CWE-918
- Updated
- 2026-11-02
NVD
7.7
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
- Record
CVE-2026-21887- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
OSV
7.7
OpenCTI has a Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
- Record
CVE-2026-21887- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
OSVGHSA-ffm6-vvph-g5f5
7.7
OpenCTI has Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
Summary
The OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs.
This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems.
Impact
OpenCTI’s data ingestion feature can allow an attacker to make the application send HTTP requests to arbitrary internal or external endpoints. This means an attacker could reach internal services that are not exposed publicly, such as Elasticsearch, Redis, or RabbitMQ, and potentially extract sensitive data or manipulate internal components. In cloud environments, the attacker could target metadata services like AWS, Azure, or GCP to obtain credentials and configuration details, which could lead to full compromise of the infrastructure. Even though the SSRF is semi-blind and the attacker may not see the full response, the ability to interact with internal services can enable enumeration, data exfiltration, and in some cases remote code execution if internal APIs expose dangerous functionality.
- Record
GHSA-ffm6-vvph-g5f5- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-20, CWE-918
- Updated
- 2026-11-02
OSVPYSEC-2026-118
7.7
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
- Record
PYSEC-2026-118- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pyctiPyPI |
before 6.8.16 | 6.8.16 |
pyctiPyPI |
before 6.8.16, plus listed versions 1.2.11.2.111.2.121.2.131.2.14 Show 45 moreShow less1.2.151.2.21.2.41.2.92.0.02.0.12.0.22.0.32.1.102.1.112.1.122.1.132.1.32.1.42.1.52.1.62.1.72.1.82.1.93.0.03.0.13.0.23.0.33.1.03.1.13.1.23.2.03.2.13.2.23.2.33.2.43.2.53.2.63.2.73.3.03.3.13.3.23.3.34.0.04.0.14.0.24.0.34.0.44.0.54.0.6 |
6.8.16 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-21887 is a high vulnerability (CVSS 7.7) in Citeum Opencti, published March 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. Fixed in pycti 6.8.16.
References
github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-ffm6-vvph-g5f5
nvd.nist.gov/vuln/detail/CVE-2026-21887
github.com/pypa/advisory-database/tree/main/vulns/pycti/PYSEC-2026-118.yaml
github.com/advisories/GHSA-ffm6-vvph-g5f5
github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21887.json
github.com/OpenCTI-Platform/opencti
Left out here: 307 versions. The JSON record has them.