Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-32236 is a low-severity SSRF (CWE-918) vulnerability in Linuxfoundation Backstage. Its CVSS base score is 1.7 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 22th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-32236 is a Server-Side Request Forgery (SSRF) vulnerability, classified under CWE-918, affecting the @backstage/plugin-auth-backend component of Backstage, an open framework for building developer portals. The issue exists in versions prior to 0.27.1 when the experimental configuration auth.experimentalClientIdMetadataDocuments.enabled is set to true. During Client ID Metadata Document (CIMD) metadata fetches, the plugin validates the initial client_id hostname against private IP ranges but fails to apply the same checks after HTTP redirects, with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
Any network-accessible attacker can exploit this vulnerability without authentication or user interaction by triggering a CIMD metadata fetch with a malicious client_id that redirects to internal resources. While the attacker cannot read the response body of the internal request, cannot control request headers or method, and the feature requires explicit enabling via an off-by-default experimental flag, successful exploitation enables the server to connect to unintended internal endpoints, potentially leading to high confidentiality impacts such as network reconnaissance.
The vulnerability is patched in @backstage/plugin-auth-backend version 0.27.1, as detailed in the GitHub security advisory GHSA-qp4c-xg64-7c6x and the fixing commit 17038abf2dfdb4abc08a59b1c95af39851de0e07. Deployments that restrict allowedClientIdPatterns to specific trusted domains are unaffected, providing a key mitigation for those not yet upgraded.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-11673
Vulnerability Data
Backstage is an open framework for building developer portals. Prior to 0.27.1, a Server-Side Request Forgery (SSRF) vulnerability exists in @backstage/plugin-auth-backend when auth.experimentalClientIdMetadataDocuments.enabled is set to true. The CIMD metadata fetch validates the initial client_id hostname against private IP ranges…
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but does not apply the same validation after HTTP redirects. The practical impact is limited. The attacker cannot read the response body from the internal request, cannot control request headers or method, and the feature must be explicitly enabled via an experimental flag that is off by default. Deployments that restrict allowedClientIdPatterns to specific trusted domains are not affected. Patched in @backstage/plugin-auth-backend version 0.27.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
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.