CVE-2026-48978
Description
A flaw was found in oras-go. The auth.Client in oras-go does not properly validate the scheme or host of the realm URL provided in a registry's WWW-Authenticate: Bearer challenge. A remote attacker, operating a malicious registry or performing a man-in-the-middle attack, could exploit this to perform Server-Side Request Forgery (SSRF) against internal networks, potentially disclosing sensitive information. Additionally, the flaw could lead to a Transport Layer Security (TLS) downgrade, causing user credentials to be sent over plaintext.
Statement
A flaw was found in oras-go. The auth.Client follows the realm URL from a registry's Bearer challenge without validating scheme or host, enabling SSRF to internal networks and TLS downgrade attacks.
Mitigation
Upgrade to oras-go v2.6.1 or later.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.1 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | Low | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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