safeurl is Missing IPv6 CIDR Ranges in Blocklist

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · 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 · score source

EPSS

• CVE-2026-54452: 0.52% estimated exploitation activity in the next 30 days; percentile 44.29 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

15 Jul 2026, 21:58 UTC

Last modified by the source

15 Jul 2026, 21:58 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xgch-x3mx-cm3c

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# Patch Next advisory brief: CVE-2026-54452

Advisory: safeurl is Missing IPv6 CIDR Ranges in Blocklist
IDs: CVE-2026-54452, GHSA-xgch-x3mx-cm3c
Record: https://patchnext.com/advisories/cve-2026-54452 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/doyensec/safeurl 0.2.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/doyensec/safeurl: affected < 0.2.4; fixed in 0.2.4

## Suggested inspection (read-only)
- Go github.com/doyensec/safeurl: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/doyensec/safeurl.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xgch-x3mx-cm3c (GitHub-reviewed advisory GHSA-xgch-x3mx-cm3c lists affected ranges: Go github.com/doyensec/safeurl >=0 <0.2.4)

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