---
cve: "CVE-2026-54430"
severity: "MEDIUM"
cvss: 5.1
epss: "12%"
vendor: "OpenIDC"
kev: false
exploited: false
published: "2026-07-02 11:16:16"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-13T23:49:17+02:00"
---

# CVE-2026-54430

> 5.1 MEDIUM · 🧪 PoC

## Beschreibung

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

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 347507ac5b51f48c2933bbe49b2ee07c2af4712b (Commit)

## Referenzen

- <https://cert.pl/en/posts/2026/07/CVE-2026-54430>
- <https://github.com/OpenIDC/liboauth2>
- <https://github.com/OpenIDC/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-54430) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_