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
Real-World Exposure
github.com/doyensec/safeurlReal-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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/doyensec/safeurl | all versions | 0.2.4 |
Detection & mitigation playbook
Open-source dependencyDetect
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.
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.
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.
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
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.