CVE-2026-54430 | liboauth2 is vulnerable to Server-Side Request Forgery in oa… | CVSS 5.1 MEDIUM

Description

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

Metadata

CVE ID: CVE-2026-54430
State: PUBLISHED
Assigner: CERT-PL
Reserved: 2026-06-15 13:08 UTC
Published: 2026-07-02 10:30 UTC
Last updated: 2026-07-02 12:17 UTC
Primary CWE: CWE-918
CWE-918 Server-Side Request Forgery (SSRF)
Vendor / Product: OpenIDC / liboauth2
Sources: cve.org · NVD

Severity & Metrics

5.1 MEDIUM CVSS 4.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
OpenIDC	liboauth2	—	0 < 2.3.0

Weakness (CWE)

CWE	Source	Description
CWE-918	cna	CWE-918 Server-Side Request Forgery (SSRF)

CVSS scores (1)

Score	Severity	Version	Source	Vector
5.1	MEDIUM	4.0	cna	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N

References (3)