Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🐹 Go
Not in CISA KEV

CVE-2026-54452

CVE-2026-54452 is a security vulnerability in github.com/doyensec/safeurl. O3 Security confirms whether CVE-2026-54452 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

safeurl is Missing IPv6 CIDR Ranges in Blocklist

Also known asGO-2026-5997
Published
Jul 15, 2026
Updated
Jul 21, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Jul 21, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐹github.com/doyensec/safeurl

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/doyensec/safeurlall versions0.2.4

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/doyensec/safeurl. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update github.com/doyensec/safeurl to 0.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54452 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2026-54452 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-54452. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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. ### R
O3 Security · Impact-Aware SCA

Is CVE-2026-54452 in your dependencies?

O3 detects CVE-2026-54452 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

CVE-2026-54452: safeurl is Missing IPv6 CIDR… | O3 Security