CVE-2026-5052 | Vault Vulnerable to Server-Side Request Forgery in ACME Challenge Validation via Attacker-Controlled DNS

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.

Published: 2026-04-17 Last update: 2026-04-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-5052 is rated Low Risk (21.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-5052

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-17 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-5052

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 4.0 [email protected]

Weakness enumeration for CVE-2026-5052

GitHub Security Advisory for CVE-2026-5052

GHSA-8r5m-3f66-qpr3 · Severity: medium · Ecosystem: go — HashiCorp Vault has Server-Side Request Forgery in ACME Challenge Validation via Attacker-Controlled DNS

OS Trackers for CVE-2026-5052

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2026-5052

Affected software / configurations for CVE-2026-5052

Vendor Product Version Raw CPE
hashicorp vault >= 1.14.0, < 1.19.16 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*
hashicorp vault >= 1.14.0, < 2.0.0 cpe:2.3:a:hashicorp:vault:*:*:*:*:-:*:*:*
hashicorp vault >= 1.20.0, < 1.20.10 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*
hashicorp vault >= 1.21.0, < 1.21.5 cpe:2.3:a:hashicorp:vault:*:*:*:*:enterprise:*:*:*

References for CVE-2026-5052

cvelogic Threat Intelligence