CVE-2026-54452: Github.com/doyensec/safeurl Safeurl Is Missing IPv6 CIDR Vulnerability

MODERATE
Advisory Identifier: GHSA-xgch-x3mx-cm3c
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CWE-918
Published
Advisory Summary

CVE-2026-54452 is a MODERATE safeurl is missing ipv6 cidr vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Github.com/doyensec/safeurl libraries in the Go ecosystem. The issue involves safeurl is missing ipv6 cidr ranges in blocklist. Remediation is available by upgrading affected packages to version 0.2.4.

CVE-2026-54452 at a Glance

CVE Identifier CVE-2026-54452
GHSA Identifier GHSA-xgch-x3mx-cm3c
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product Github.com/doyensec/safeurl
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2026-54452

To remediate this vulnerability, upgrade all affected Github.com/doyensec/safeurl dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/doyensec/safeurl fixed: 0.2.4 
Upgrade github.com/doyensec/safeurl to 0.2.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/doyensec/safeurl

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-54452, inspect your project dependencies for Github.com/doyensec/safeurl:

inspect dependencies for github.com/doyensec/safeurl

Analyze the terminal output to locate any version of Github.com/doyensec/safeurl in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.2.4), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-918: Server-Side Request Forgery (SSRF), where 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. In Github.com/doyensec/safeurl, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The `privateNetworks` blocklist was found to be missing newly added CIDR ranges. More specifically, the following CIDR ranges were not being blocked: - `64:ff9b:1::/48`: NAT64 local-use prefix (RFC 8215) - `5f00::/16`: Segment Routing (SRv6) SIDs (RFC 9602) - `3fff::/20`: documentation prefix (RFC 9637) - `100:0:0:1::/64`: Dummy IPv6 Prefix (RFC 9780) ### Impact If exploited, an attacker would potentially be able to reach resources hosted on the IPs residing in the missing ranges. ### Workarounds Disable IPv6 by setting `EnableIPv6(false)`. This is the default behavior of the library. ### Resolution Upgrade to v0.2.4 ### Credits safeurl thanks @tonghuaroot for reporting.

CVE-2026-54452 Affected Github.com/doyensec/safeurl Versions

1 component(s)
Fixed Versions:
0.2.4
Product / Package Ecosystem Affected Versions Fixed Version
github.com/doyensec/safeurl
golang/github.com/doyensec/safeurl
Go
< 0.2.4
0.2.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/doyensec/safeurl/security/advisories/GHSA-xgch-x3mx-cm3c
Github.com/doyensec/safeurl Source Repository REPOSITORY
https://github.com/doyensec/safeurl
Github.com/doyensec/safeurl Release RELEASE
https://github.com/doyensec/safeurl/releases/tag/v0.2.4

Frequently Asked Questions

What is CVE-2026-54452?
CVE-2026-54452 is a security vulnerability in Github.com/doyensec/safeurl involving safeurl is Missing IPv6 CIDR Ranges in Blocklist under CWE-918: Server-Side Request Forgery (SSRF).
Which Github.com/doyensec/safeurl versions are affected?
Affected versions include releases prior to 0.2.4 across affected packages: github.com/doyensec/safeurl.
What version fixes CVE-2026-54452?
Upgrading to 0.2.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/doyensec/safeurl affected?
Yes, github.com/doyensec/safeurl is affected in releases prior to 0.2.4. Upgrade your dependency to 0.2.4 or later.
What CWE is associated with CVE-2026-54452?
CVE-2026-54452 is classified under CWE-918: Server-Side Request Forgery (SSRF) (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.).
How can I check Go dependencies for CVE-2026-54452?
Run the dependency tree command: 'inspect dependencies for github.com/doyensec/safeurl'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xgch-x3mx-cm3c",
  "modified" : "2026-07-15T21:58:03Z",
  "published" : "2026-07-15T21:58:03Z",
  "aliases" : [ "CVE-2026-54452" ],
  "summary" : "safeurl is Missing IPv6 CIDR Ranges in Blocklist",
  "details" : "The `privateNetworks` blocklist was found to be missing newly added CIDR ranges. More specifically, the following CIDR ranges were not being blocked:\n- `64:ff9b:1::/48`: NAT64 local-use prefix (RFC 8215)\n- `5f00::/16`: Segment Routing (SRv6) SIDs (RFC 9602)\n- `3fff::/20`: documentation prefix (RFC 9637)\n- `100:0:0:1::/64`: Dummy IPv6 Prefix (RFC 9780)\n\n### Impact\nIf exploited, an attacker would potentially be able to reach resources hosted on the IPs residing in the missing ranges.\n\n### Workarounds\nDisable IPv6 by setting `EnableIPv6(false)`. This is the default behavior of the library.\n\n### Resolution\nUpgrade to v0.2.4\n\n### Credits\nsafeurl thanks @tonghuaroot for reporting.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/doyensec/safeurl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.2.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/doyensec/safeurl/security/advisories/GHSA-xgch-x3mx-cm3c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/doyensec/safeurl"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/doyensec/safeurl/releases/tag/v0.2.4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-15T21:58:03Z",
    "nvd_published_at" : null
  }
}