Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:NSummary
CVE-2026-27023 is a medium-severity SSRF (CWE-918) vulnerability in Twenty Twenty. Its CVSS base score is 5.0 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SC-7 (Boundary Protection) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9845
Vulnerability Data
Twenty is an open source CRM. Prior to version 1.18, the SSRF protection in SecureHttpClientService validated request URLs at the request level but did not validate redirect targets. An authenticated user who could control outbound request URLs (e.g., webhook endpoints,…
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image URLs) could bypass private IP blocking by redirecting through an attacker-controlled server. This issue has been patched in version 1.18.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
SSRF bypass via unvalidated redirects directly enables exploitation of the public-facing CRM application to access internal resources.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Enforces information flow policies that block requests (including redirects) to private/internal addresses, directly stopping the SSRF bypass described.
Implements boundary protection rules that restrict outbound connections to internal IP ranges regardless of how the target is reached (initial URL or redirect).
Requires validation of all URL inputs and derived targets (redirects) to reject private addresses, addressing the incomplete validation in SecureHttpClientService.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.