CVE-2026-5052

Description

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 Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16.

CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Vendor	Product	Versions
hashicorp	vault	1.14.0 — 1.19.16
hashicorp	vault	1.14.0 — 2.0.0
hashicorp	vault	1.20.0 — 1.20.10
hashicorp	vault	1.21.0 — 1.21.5

References

Advisories & Patches

https://discuss.hashicorp.com/t/hcsec-2026-06-vault-vulnerable-to-server-side-request-forgery-in-acme-challenge-validation-via-attacker-controlled-dns/77343

Frequently Asked Questions

What is CVE-2026-5052? +

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 Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-5052? +

CVE-2026-5052 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-5052? +

CVE-2026-5052 affects products from hashicorp, specifically: vault. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-5052? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-40564

Files or Directories Accessible to External Parties, Server-Side Request Forgery (SSRF) vulnerability in Apache Flink Kubernetes Operator. The FlinkSessionJob jarURI …

CVE-2026-2264

A vulnerability in the Google Cloud Apigee SetIntegrationRequest policy allowed remote attackers to perform Server-Side Request Forgery (SSRF) and exfiltrate …

CVE-2026-42335

MaxKB is an open-source AI assistant for enterprise. Prior to 2.8.1, MaxKB v2.8.0 and prior are vulnerable to a server-side …

CVE-2026-42336

MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) …

CVE-2026-45412

MaxKB is an open-source AI assistant for enterprise. Prior to 2.9.1, SSRF via work_flow_template Import. Authenticated users can supply arbitrary …

CVE-2026-8606

A Server-Side Request Forgery (SSRF) vulnerability was identified in GitHub Enterprise Server that allowed an attacker to cause the server …