# CVE-2026-123542: OpenAM PKCE bypass in OAuth 2.0 device authorization flow

Source: https://junglewise.ai/threats/cve-2026-123542-openam-before-16-1-4-fails-to-enforce-pkce-in-the-oauth-2-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-08. Updated: 2026-11-08  
License: CC BY 4.0 with a link back

CVE-2026-123542 · Severity: medium · CVSS 6.8 · Published 2026-11-08

OpenAM is an identity and access management platform that provides OAuth 2.0 authentication. The device authorization flow allows users to approve access on shared or less-capable devices. A flaw fails to validate the cryptographic proof (PKCE verifier) when exchanging device codes for tokens, allowing attackers who obtain an approved device code from logs or shared device storage to impersonate users and gain unauthorized API access.

Technologies: [Open Identity Platform OpenAM](https://junglewise.ai/threats/technologies/openam). Vendors: [Open Identity Platform](https://junglewise.ai/threats/vendors/open-identity-platform).

## Quick answers

**Is CVE-2026-123542 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123542 being exploited in the wild.

**How severe is CVE-2026-123542?** Medium severity, with a CVSS score of 6.8, published 8 November 2026.

**Which products and versions are affected?** Open Identity Platform OpenAM before 16.1.4.

**Is there a fix for CVE-2026-123542?** Yes: fixed in 16.1.4. Until then: Use HTTPS for all device-flow client traffic, prevent device codes from being written to client or proxy logs, restrict device code grants to only clients that require them, prefer confidential clients that authenticate to the token endpoint, keep device code lifetime short in OAuth 2.0 provider settings, and review tokens issued through device flow to revoke any that do not correspond to approved devices. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123542 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-123542?** Check whether you run Open Identity Platform OpenAM at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 16.1.4

Use HTTPS for all device-flow client traffic, prevent device codes from being written to client or proxy logs, restrict device code grants to only clients that require them, prefer confidential clients that authenticate to the token endpoint, keep device code lifetime short in OAuth 2.0 provider settings, and review tokens issued through device flow to revoke any that do not correspond to approved devices.

## Technical details

OpenAM's OAuth 2.0 device authorization flow accepts PKCE challenges during device code request but never validates the corresponding code verifier when the device code is exchanged for tokens. This allows an attacker who obtains an approved device code (from client logs, shared device storage, or interception) to redeem it for access and ID tokens without providing the correct verifier. Public clients without additional authentication are most vulnerable; confidential clients authenticating to the token endpoint have baseline protection.

## Affected products

- Open Identity Platform OpenAM before 16.1.4

## Timeline

- 2026-10-22: disclosed
- 2026-11-08: advisory

## References

- [https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-h93p-35jm-rj83](https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-h93p-35jm-rj83)
- [https://www.vulncheck.com/advisories/openam-before-16.1.4-pkce-bypass-in-oauth-2.0-device-authorization-flow](https://www.vulncheck.com/advisories/openam-before-16.1.4-pkce-bypass-in-oauth-2.0-device-authorization-flow)

## Related threats

- [OpenAM default credentials authentication bypass in built-in identities](https://junglewise.ai/threats/cve-2026-123553-openam-before-16-1-4-ships-built-in-identities-in-the-top-level)
- [OpenAM unauthenticated session token disclosure via WebSocket](https://junglewise.ai/threats/cve-2026-123551-openam-from-14-0-0-before-16-1-4-contains-an-information)
- [OpenAM SAML v2.0 service provider authentication bypass](https://junglewise.ai/threats/cve-2026-123550-openam-before-16-1-4-contains-an-authentication-bypass)
- [OpenAM self-registration attribute list enforcement bypass](https://junglewise.ai/threats/cve-2026-123549-openam-before-16-1-4-fails-to-enforce-the-valid-creation)
- [OpenAM open redirect via SAML RelayState](https://junglewise.ai/threats/cve-2026-123547-openam-before-16-1-4-contains-an-open-redirect-vulnerability)