# CVE-2026-54430: OpenIDC liboauth2 SSRF in oauth2_jose_jwks_aws_alb_resolve

Source: https://junglewise.ai/threats/cve-2026-54430-openidc-liboauth2-ssrf-in-oauth2-jose-jwks-aws-alb-resolve  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-02. Updated: 2026-07-02  
License: CC BY 4.0 with a link back

CVE-2026-54430 · Severity: info · CVSS 5.1 · Published 2026-07-02

liboauth2 is a library used by applications to handle OAuth 2.0 and OpenID Connect authentication. A security flaw in how it handles AWS Application Load Balancer (ALB) tokens allows an attacker to trick the server into making unauthorized web requests to internal systems. This could lead to the exposure of internal configuration data or unauthorized access to private internal services.

Vendors: [Openidc](https://junglewise.ai/threats/vendors/openidc).

## Quick answers

**Is CVE-2026-54430 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54430 being exploited in the wild.

**How severe is CVE-2026-54430?** Informational severity, with a CVSS score of 5.1, published 2 July 2026.

**Which products and versions are affected?** Openidc Liboauth2 < 2.3.0.

**Is there a fix for CVE-2026-54430?** A patch was published on 2026-07-02: Fixed in version 2.3.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54430 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-54430?** Check whether you run Openidc Liboauth2 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.

## Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in the oauth2_jose_jwks_aws_alb_resolve() function of liboauth2. The AWS ALB verifier extracts the 'signer' and 'kid' (Key ID) fields from an unverified JWT header. If the 'signer' matches a configured ARN, the 'kid' value is appended to the 'alb_base_url' without proper URL encoding or path sanitization. Because the HTTP GET request for the JWKS is issued before the JWT signature is verified, a remote attacker can provide a malicious 'kid' to force the server to perform a GET request to an arbitrary internal path. This issue is resolved in version 2.3.0 by implementing proper URL encoding for the 'kid' parameter.

## Affected products

- OpenIDC liboauth2 < 2.3.0

## Timeline

- 2026-07-02: advisory: NVD publication date
- 2026-07-02: disclosed
- 2026-07-02: patched: Fixed in version 2.3.0

## References

- [https://cert.pl/en/posts/2026/06/CVE-2026-54430](https://cert.pl/en/posts/2026/06/CVE-2026-54430)
- [https://github.com/OpenIDC/liboauth2](https://github.com/OpenIDC/liboauth2)
- [https://github.com/OpenIDC/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b](https://github.com/OpenIDC/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b)

## Related threats

- [OpenIDC liboauth2 improper security check in DPoP verifier](https://junglewise.ai/threats/cve-2026-54431-openidc-liboauth2-improper-security-check-in-dpop-verifier)