AWS Cloud Development Kit (AWS CDK) IAM OIDC custom resource allows connection to unauthorized OIDC provider

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

1.8 · CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2025-23206: 0.33% estimated exploitation activity in the next 30 days; percentile 26.37 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Users who use IAM OIDC custom resource provider package will download CA Thumbprints as part of the custom resource workflow, https://github.com/aws/aws-cdk/blob/d16482fc8a4a3e1f62751f481b770c09034df7d2/packages/%40aws-cdk/custom-resource-handlers/lib/aws-iam/oidc-handler/external.ts#L34. However, the current tls.connect method will always set rejectUnauthorized: false which is a potential security concern. CDK should follow the best practice and set rejectUnauthorized: true. However, this could be a breaking change for existing CDK applications and we should fix this with a feature flag. Note that this is marked as low severity Security advisory because the issuer url is provided by CDK users who define the CDK application. If they insist on connecting to a unauthorized OIDC provider, CDK should not disallow this. Additionally, the code block is run in a Lambda environment which mitigate the MITM attack. As a best practice, CDK should still fix this issue under a feature flag…

Published by the source

17 Jan 2025, 21:22 UTC

Last modified by the source

29 Jan 2025, 18:22 UTC

Source last checked

26 Oct 2026, 12:31 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v4mq-x674-ff73

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-v4mq-x674-ff73

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# Patch Next advisory brief: CVE-2025-23206

Advisory: AWS Cloud Development Kit (AWS CDK) IAM OIDC custom resource allows connection to unauthorized OIDC provider
IDs: CVE-2025-23206, GHSA-v4mq-x674-ff73
Record: https://patchnext.com/advisories/cve-2025-23206 (revision 3, source checked 26 Oct 2026, 12:31 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 1.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: aws-cdk-lib 2.177.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm aws-cdk-lib: affected < 2.177.0; fixed in 2.177.0

## Suggested inspection (read-only)
- `npm ls aws-cdk-lib --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on aws-cdk-lib.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-v4mq-x674-ff73 (OSV record GHSA-v4mq-x674-ff73 lists affected ranges: npm aws-cdk-lib >=0 <2.177.0 (fixed))
- Verified: https://github.com/advisories/GHSA-v4mq-x674-ff73 (GitHub-reviewed advisory GHSA-v4mq-x674-ff73 lists affected ranges: npm aws-cdk-lib >=0 <2.177.0)

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