PT-2026-54443 · Fulcio · Fulcio

Published

2026-06-30

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Updated

2026-06-30

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CVE-2026-49478

CVSS v3.1

8.7

High

VectorAV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Name of the Vulnerable Software and Affected Versions Fulcio versions prior to 1.8.6
Description Three security issues were identified in the OIDC Discovery client. First, a blind Server-Side Request Forgery (SSRF) occurs because the HTTP client used to fetch OIDC discovery metadata from the /.well-known/openid-configuration endpoint followed cross-host redirects by default, allowing requests to be sent to internal-only systems. Second, this behavior enables JWKS substitution and cache poisoning, where an attacker can manipulate the discovery flow to return a malicious jwks uri and poison the verifier cache with attacker-controlled verification keys. Third, Kubernetes ServiceAccount tokens are leaked to third-party hosts when the transport attaches the token globally during redirects or when a wildcard MetaIssuer of type kubernetes matches an external endpoint while a local Kubernetes issuer is configured.
Recommendations Update to version 1.8.6.

Fix

SSRF

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Weakness Enumeration

Related Identifiers

CVE-2026-49478
GHSA-F5MR-Q85P-6HH6

Affected Products

Fulcio