Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2026-5052 is a medium-severity SSRF (CWE-918) vulnerability in Hashicorp Vault. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 26th 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-2026-5052 is a vulnerability in HashiCorp Vault's PKI engine ACME validation process, which fails to reject local targets when issuing http-01 and tls-alpn-01 challenges. This flaw allows requests to be sent to local network targets, potentially resulting in information disclosure. The issue affects Vault Community Edition and Vault Enterprise versions prior to the fixed releases, including Community Edition 2.0.0 and Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16. It is classified under CWE-918 (Server-Side Request Forgery) with a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).
Remote unauthenticated attackers can exploit this vulnerability over the network with low complexity and no user interaction. By controlling DNS resolution, an attacker can trick Vault into directing ACME challenge validation requests to attacker-specified local network targets, enabling server-side request forgery (SSRF). Successful exploitation leads to low-impact confidentiality violations, such as disclosure of sensitive information from internal services reachable via those local targets.
HashiCorp's security advisory, detailed in HCSEC-2026-06 on their discussion forum, confirms the SSRF vulnerability in ACME challenge validation and recommends upgrading to the patched versions: Vault Community Edition 2.0.0 or Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16. No additional workarounds are specified in the available information.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-23344
Vulnerability Data
Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challenges. This may lead to these requests being sent to local network targets, potentially leading to information disclosure. Fixed in Vault Community Edition 2.0.0 and…
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Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.6V1.5.3V5.3.2V10.4.7
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.