CVE-2026-10582
Description
A flaw was found in Hugo. The security.http.urls allowlist, which controls outbound fetches, does not adequately validate the destination address of URLs. This vulnerability allows a remote attacker to supply a specially crafted URL that resolves to internal network resources. As a result, the Hugo build process can fetch internal endpoints, and the sensitive response data may be embedded and published within the generated static site, leading to information disclosure.
Mitigation
To mitigate this vulnerability, ensure that the Hugo `security.http.urls` allowlist is strictly configured to permit outbound requests only to explicitly trusted external domains. Implement network egress filtering to prevent Hugo from initiating connections to internal, loopback, or private IP address ranges. This can be achieved by configuring firewall rules or network policies to block outbound traffic from the Hugo environment to RFC1918 addresses and other internal network segments.
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 | 7.4 | N/A | 7.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Changed | N/A | Changed |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/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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