Vulnerabilities in pkg:nuget/Duende.AccessTokenManagement

PACKAGE
Advisory Identifier: GHSA-qxj7-2x7w-3mpp
Advisory Summary

CVE-2025-26620 is a MODERATE duende.accesstokenmanagement race condition when concurrently vulnerability (CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition) affecting Duende.AccessTokenManagement libraries in the NuGet ecosystem. The issue involves duende.accesstokenmanagement race condition when concurrently retrieving customized client credentials access tokens. Remediation is available by upgrading affected packages to version 3.2.0.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:nuget/Duende.AccessTokenManagement

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:nuget/Duende.AccessTokenManagement. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-qxj7-2x7w-3mpp CVE-2025-26620 MODERATE Duende.AccessTokenManagement race condition when concurrently retrieving customized Client Credentials Access Tokens

CVE-2025-26620 at a Glance

CVE Identifier CVE-2025-26620
GHSA Identifier GHSA-qxj7-2x7w-3mpp
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
Affected Product Duende.AccessTokenManagement
Package Ecosystem NuGet
Published Date
Last Updated

How to Fix CVE-2025-26620

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

Duende.AccessTokenManagement fixed: 3.2.0
Upgrade Duende.AccessTokenManagement to 3.2.0
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 Duende.AccessTokenManagement

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-26620, inspect your project dependencies for Duende.AccessTokenManagement:

inspect dependencies for Duende.AccessTokenManagement

Analyze the terminal output to locate any version of Duende.AccessTokenManagement in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.2.0), 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-367: Time-of-check Time-of-use (TOCTOU) Race Condition, where the product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. In Duende.AccessTokenManagement, 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

### Summary Duende.AccessTokenManagement contains a race condition when requesting access tokens using the client credentials flow. Concurrent requests to obtain an access token using differing protocol parameters can return access tokens obtained with the wrong scope, resource indicator, or other protocol parameters. Such usage is somewhat atypical, and only a small percentage of users are likely to be affected. ### Details Duende.AccessTokenManagement can request access tokens using the client credentials flow in several ways. In basic usage, the client credentials flow is configured once and the parameters do not vary. In more advanced situations, requests with varying protocol parameters may be made by calling specific overloads of these methods: - `HttpContext.GetClientAccessTokenAsync()` - `IClientCredentialsTokenManagementService.GetAccessTokenAsync()` There are overloads of both of these methods that accept a `TokenRequestParameters` object that customizes token request parameters. However, concurrent requests with varying `TokenRequestParameters` will result in the same token for all concurrent calls. ### Upgrading Most users can simply update the NuGet package to the latest version. Customizations of the `IClientCredentialsTokenCache` that derive from the default implementation (`DistributedClientCredentialsTokenCache`) will require a small code change, as its constructor was changed to add a dependency on the `ITokenRequestSynchronization` service. The synchronization service will need to be injected into the derived class and passed to the base constructor. ### Impact The impact of this vulnerability depends on how Duende.AccessTokenManagement is used and on the security architecture of the solution. Most users will not be vulnerable to this issue. More advanced users may run into this issue by calling the methods specified above with customized token request parameters. The impact of obtaining an access token with different than intended protocol parameters will vary depending on application logic, security architecture, and the authorization policy of the resource servers. Thank you to **Michael Dimoudis** of **PageUp** for finding this issue and responsibly disclosing it!

CVE-2025-26620 Affected Duende.AccessTokenManagement Versions

1 component(s)
Fixed Versions:
3.2.0
Product / Package Ecosystem Affected Versions Fixed Version
Duende.AccessTokenManagement
NuGet
< 3.2.0
3.2.0

References

Frequently Asked Questions

What is CVE-2025-26620?
CVE-2025-26620 is a security vulnerability in Duende.AccessTokenManagement involving Duende.AccessTokenManagement race condition when concurrently retrieving customized Client Credentials Access Tokens under CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition.
Which Duende.AccessTokenManagement versions are affected?
Affected versions include releases prior to 3.2.0 across affected packages: Duende.AccessTokenManagement.
What version fixes CVE-2025-26620?
Upgrading to 3.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Duende.AccessTokenManagement affected?
Yes, Duende.AccessTokenManagement is affected in releases prior to 3.2.0. Upgrade your dependency to 3.2.0 or later.
What CWE is associated with CVE-2025-26620?
CVE-2025-26620 is classified under CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition (The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.).
How can I check NuGet dependencies for CVE-2025-26620?
Run the dependency tree command: 'inspect dependencies for Duende.AccessTokenManagement'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qxj7-2x7w-3mpp",
  "modified" : "2025-02-19T17:47:19Z",
  "published" : "2025-02-19T17:47:19Z",
  "aliases" : [ "CVE-2025-26620" ],
  "summary" : "Duende.AccessTokenManagement race condition when concurrently retrieving customized Client Credentials Access Tokens",
  "details" : "### Summary\nDuende.AccessTokenManagement contains a race condition when requesting access tokens using the client credentials flow. Concurrent requests to obtain an access token using differing protocol parameters can return access tokens obtained with the wrong scope, resource indicator, or other protocol parameters. Such usage is somewhat atypical, and only a small percentage of users are likely to be affected.\n\n### Details\nDuende.AccessTokenManagement can request access tokens using the client credentials flow in several ways. In basic usage, the client credentials flow is configured once and the parameters do not vary. In more advanced situations, requests with varying protocol parameters may be made by calling specific overloads of these methods:\n\n- `HttpContext.GetClientAccessTokenAsync()`\n- `IClientCredentialsTokenManagementService.GetAccessTokenAsync()`\n\nThere are overloads of both of these methods that accept a `TokenRequestParameters` object that customizes token request parameters. However, concurrent requests with varying `TokenRequestParameters` will result in the same token for all concurrent calls.\n\n\n### Upgrading\nMost users can simply update the NuGet package to the latest version. Customizations of the `IClientCredentialsTokenCache` that derive from the default implementation (`DistributedClientCredentialsTokenCache`) will require a small code change, as its constructor was changed to add a dependency on the `ITokenRequestSynchronization` service. The synchronization service will need to be injected into the derived class and passed to the base constructor.\n\n### Impact\nThe impact of this vulnerability depends on how Duende.AccessTokenManagement is used and on the security architecture of the solution. Most users will not be vulnerable to this issue. More advanced users may run into this issue by calling the methods specified above with customized token request parameters. The impact of obtaining an access token with different than intended protocol parameters will vary depending on application logic, security architecture, and the authorization policy of the resource servers.\n\nThank you to **Michael Dimoudis** of **PageUp** for finding this issue and responsibly disclosing it!",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Duende.AccessTokenManagement"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/DuendeSoftware/foss/security/advisories/GHSA-qxj7-2x7w-3mpp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-26620"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/DuendeSoftware/foss/commit/a33332ddec0ebf3c048ba85427e3c77d47c68dac"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/DuendeSoftware/foss"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-367" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-02-19T17:47:19Z",
    "nvd_published_at" : "2025-02-18T18:15:36Z"
  }
}