Medium [CVE-2026-54430] Server-Side Request Forgery allows unauthorized internal network access
This medium-severity Red Hat Linux advisory covers CVE-2026-54430.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
liboauth2 is vulnerable to Server-Side Request Forgery in oauth2_jose_jwks_aws_alb_resolve() function. The AWS ALB verifier reads both signer and kid from the unverified JWT header.
If signer matches the configured ARN, kid is appended to alb_base_url without URL encoding or path sanitization, and the HTTP GET is issued before signature verification. This allows an attacker to force the server to send a GET request to an attacker-chosen internal path.
This issue was fixed in version 2.3.0 An attacker who can present a crafted JWT to an endpoint using AWS ALB verification could force the server to issue GET requests to unintended internal paths, potentially disclosing limited information from internal services.
This Moderate flaw in liboauth2 allows for Server-Side Request Forgery (SSRF) when an application uses AWS ALB JWT verification. This requires the vulnerable component to be configured with AWS ALB JWT verification.
Red Hat severity: Moderate — CVSS 5.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N). Weakness: CWE-918.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
Mitigation checklist
- Restrict network access to the application endpoint that processes AWS ALB-signed JWTs to trusted sources only. If the AWS ALB verification feature (oauth2_jose_jwks_aws_alb_resolve) is not required, disable it in the liboauth2 configuration. Upgrade to liboauth2 version 2.3.0 or later to fully resolve this vulnerability.
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.