CVE-2026-5052Network attack vector

Local service probing via unfiltered ACME targets

Published Apr 17, 2026 · Updated Apr 17, 2026

Server-side request forgery in HashiCorp Vault and Vault Enterprise allows remote attackers to probe local services via ACME validation. The PKI ACME HTTP-01 and TLS-ALPN-01 validators dialed literal addresses and attacker-controlled DNS results without rejecting loopback, link-local, multicast, unspecified, or other non-global-unicast targets. The challenge endpoint is unauthenticated in some configurations and otherwise requires an EAB token; successful requests can disclose information from reachable local services.

CVSS severity5.3
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in HashiCorp Vault and Vault Enterprise allows remote attackers to probe local services via ACME validation. The PKI ACME HTTP-01 and TLS-ALPN-01 validators dialed literal addresses and attacker-controlled DNS results without rejecting loopback, link-local, multicast, unspecified, or other non-global-unicast targets. The challenge endpoint is unauthenticated in some configurations and otherwise requires an EAB token; successful requests can disclose information from reachable local services.

The record

CVE
CVE-2026-5052
Published
Apr 17, 2026
Updated
Apr 17, 2026
Vendor
HashiCorp
Product
Vault
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.15.0 <2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HashiCorp · Vaultversion=1.15.0 <2.0.0
HashiCorp · Vault Enterpriseversion=1.15.0 <2.0.0 changes=[{"at":"1.19.16","status":"unaffected"},{"at":"1.20.10","status":"unaffected"},{"at":"1.21.5","status":"unaffected"}]

Published CVSS scores

8.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
5.3HashiCorp Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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