---
cve: "CVE-2026-49478"
severity: "HIGH"
cvss: 8.7
epss: "0.2%"
vendor: "sigstore"
kev: false
exploited: false
published: "2026-08-13 13:19:09"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T21:44:08+02:00"
---

# CVE-2026-49478

> 8.7 HIGH · 🧪 PoC

## Beschreibung

Fulcio is a certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Versions through 1.8.5 improperly follow cross-host redirects and attach Kubernetes ServiceAccount tokens during OIDC discovery, allowing a malicious or compromised issuer to perform blind SSRF, substitute and cache malicious JWKS keys, or disclose ServiceAccount tokens to external hosts. Version 1.8.6 blocks cross-host redirects, restricts token injection, and restricts local token loading. No known workarounds are available.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 378c654f48c3bafdced04ead7010aab2cb4c6ca1 (Commit)

## Referenzen

- <https://github.com/sigstore/fulcio/security/advisories/GHSA-f5mr-q85p-6hh6>
- <https://github.com/sigstore/fulcio/pull/2354>
- <https://github.com/sigstore/fulcio/commit/378c654f48c3bafdced04ead7010aab2cb4c6ca1>
- <https://github.com/sigstore/fulcio/releases/tag/v1.8.6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-49478) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_