CVE-2026-4525: Github.com/hashicorp/vault HashiCorp Vault May Expose Tokens Vulnerability

HIGH
Advisory Identifier: GHSA-72gw-fmmr-c4r4
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CVSS 7.5
CWE-201
Published
Advisory Summary

CVE-2026-4525 is a HIGH (CVSS 7.5) hashicorp vault may expose tokens vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting Github.com/hashicorp/vault libraries in the Go ecosystem. The issue involves hashicorp vault may expose tokens to auth plugins due to incorrect header sanitization. Remediation is available in the latest vendor maintenance releases.

CVE-2026-4525 at a Glance

CVE Identifier CVE-2026-4525
GHSA Identifier GHSA-72gw-fmmr-c4r4
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product Github.com/hashicorp/vault
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-4525

To remediate this vulnerability, upgrade all affected Github.com/hashicorp/vault dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/hashicorp/vault fixed: Latest secure release 
Upgrade github.com/hashicorp/vault to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/hashicorp/vault

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-4525, inspect your project dependencies for Github.com/hashicorp/vault:

inspect dependencies for github.com/hashicorp/vault

Analyze the terminal output to locate any version of Github.com/hashicorp/vault in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. In Github.com/hashicorp/vault, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

If a Vault auth mount is configured to pass through the "Authorization" header, and the "Authorization" header is used to authenticate to Vault, Vault forwarded the Vault token to the auth plugin backend. Fixed in 2.0.0, 1.21.5, 1.20.10, and 1.19.16.

CVE-2026-4525 Affected Github.com/hashicorp/vault Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/hashicorp/vault
golang/github.com/hashicorp/vault
Go
≥ 0.11.2
≤ 1.21.4

References

NVD — CVE-2026-4525 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4525
Github.com/hashicorp/vault Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-4525
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2459107
discuss.hashicorp.com/t/hcsec-2026-07-vau... WEB
https://discuss.hashicorp.com/t/hcsec-2026-07-vault-may-expose-tokens-to-auth-plugins-due-to-incorrect-header-sanitization/77344
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-72gw-fmmr-c4r4
Github.com/hashicorp/vault Source Repository REPOSITORY
https://github.com/hashicorp/vault
Github.com/hashicorp/vault Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4525.json

Frequently Asked Questions

What is CVE-2026-4525?
CVE-2026-4525 is a security vulnerability in Github.com/hashicorp/vault involving HashiCorp Vault May Expose Tokens to Auth Plugins Due to Incorrect Header Sanitization under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which Github.com/hashicorp/vault versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/hashicorp/vault.
What version fixes CVE-2026-4525?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/hashicorp/vault affected?
Yes, github.com/hashicorp/vault is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-4525?
CVE-2026-4525 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-4525?
CVE-2026-4525 is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check Go dependencies for CVE-2026-4525?
Run the dependency tree command: 'inspect dependencies for github.com/hashicorp/vault'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-72gw-fmmr-c4r4",
  "modified" : "2026-07-21T13:47:54Z",
  "published" : "2026-04-17T06:31:07Z",
  "aliases" : [ "CVE-2026-4525" ],
  "summary" : "HashiCorp Vault May Expose Tokens to Auth Plugins Due to Incorrect Header Sanitization",
  "details" : "If a Vault auth mount is configured to pass through the \"Authorization\" header, and the \"Authorization\" header is used to authenticate to Vault, Vault forwarded the Vault token to the auth plugin backend. Fixed in 2.0.0, 1.21.5, 1.20.10, and 1.19.16.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/hashicorp/vault"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.11.2"
      }, {
        "last_affected" : "1.21.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4525"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-4525"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2459107"
  }, {
    "type" : "WEB",
    "url" : "https://discuss.hashicorp.com/t/hcsec-2026-07-vault-may-expose-tokens-to-auth-plugins-due-to-incorrect-header-sanitization/77344"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-72gw-fmmr-c4r4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hashicorp/vault"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4525.json"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-18T00:53:01Z",
    "nvd_published_at" : "2026-04-17T04:16:09Z"
  }
}