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
{
"cna_assigner": "CERT-PL",
"cwe_ids": [
"CWE-918"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54430.json"
}"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54430.json"
[
{
"deprecated": false,
"digest": {
"function_hash": "310001169713942613343435151233392444484",
"length": 1239
},
"id": "CVE-2026-54430-082ea3a8",
"signature_type": "Function",
"signature_version": "v1",
"source": "https://github.com/openidc/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b",
"target": {
"file": "src/jose.c",
"function": "oauth2_jose_jwks_aws_alb_resolve"
}
},
{
"deprecated": false,
"digest": {
"line_hashes": [
"300782311466481198031019369587407341335",
"121593882326356607658898739081028212141",
"144918086941886362552307221027761693930",
"3618328312005784352581273794445680450",
"199649873056629801079065975266881212353",
"179262542926059421241759038069143382221",
"71972938115036490850486121777060821154",
"123276757899723470177019514006078774905",
"263632559640752313388992170985475915768",
"305138988736990169084066309097346446257",
"11402096707507145550694885126300127758",
"158025553772314100289543362685183048192",
"104146115157386064007737405664140634588",
"120773239811982707303597383826806095175",
"68334545154680162432049627675389874689",
"243027684613140417202696302056330927767",
"315274418919029771893744850077596020271",
"105387709087907887184981019173246142867",
"157474443155713369137405672583884754564",
"227704989154753889667959283309090548318"
],
"threshold": 0.9
},
"id": "CVE-2026-54430-62c42076",
"signature_type": "Line",
"signature_version": "v1",
"source": "https://github.com/openidc/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b",
"target": {
"file": "src/jose.c"
}
}
]
"2026-08-12T16:41:13Z"