CVE-2026-54452
Received Received - Intake

SSRF Bypass via IPv6 Range Omission in safeurl

Publication date: 2026-09-14

Last updated on: 2026-09-14

Assigner: GitHub, Inc.

Description
safeurl is a server-side request forgery protection library. Prior to 0.2.4, the privateNetworks list in ip.go omits the IPv6 ranges 64:ff9b:1::/48, 5f00::/16, 3fff::/20, and 100:0:0:1::/64. When an application enables IPv6 with EnableIPv6(true), an attacker-controlled destination in one of these ranges is not recognized as non-public and can pass the SSRF destination check, potentially allowing access to resources hosted within the omitted ranges. IPv6 is disabled by default, and configurations that retain EnableIPv6(false) are not exposed to this bypass. This issue is fixed in version 0.2.4.

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Meta Information

Published
2026-09-14
Last Modified
2026-09-14
Generated
2026-09-14
AI Q&A
2026-09-14
EPSS Evaluated
N/A
NVD
CVE-2026-54452
EUVD
EUVD-2026-77630

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
doyensec safeurl to 0.2.4 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

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Executive Summary

This is a Server-Side Request Forgery (SSRF) vulnerability in the safeurl library versions below 0.2.4. The privateNetworks list in the code omits certain IPv6 ranges, allowing attackers to bypass SSRF protections and access resources within those ranges when IPv6 is enabled. The missing ranges include 64:ff9b:1::/48, 5f00::/16, 3fff::/20, and 100:0:0:1::/64.

Detection Guidance

Check if your safeurl library version is below 0.2.4. Use commands like 'npm list safeurl' or 'pip show safeurl' to verify the installed version. If IPv6 is enabled, inspect network logs for requests to IPv6 ranges 64:ff9b:1::/48, 5f00::/16, 3fff::/20, or 100:0:0:1::/64.

Impact Analysis

An attacker could exploit this to bypass network restrictions and access internal resources hosted on the omitted IPv6 ranges. This could lead to unauthorized data access, internal service exposure, or further network compromise. The impact is limited to systems using safeurl with IPv6 enabled.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, potentially violating GDPR's data protection requirements or HIPAA's security rules for protected health information. Organizations using affected versions may face compliance violations if exploited.

Mitigation Strategies

Upgrade the safeurl library to version 0.2.4 or later. Alternatively, disable IPv6 by setting EnableIPv6(false) in your application configuration. This is the default behavior and mitigates the issue.

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