CVE-2026-48978
oras-go: Malicious registry can hijack Bearer token realm to exfiltrate credentials and refresh tokens
Blast Radius
oras.land/oras-go/v2🐹oras.land/oras-goReal-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
oras-go is a Go library for managing OCI artifacts. Prior to 2.6.1, auth.Client follows the realm URL from a registry's WWW-Authenticate: Bearer challenge without validating the scheme or host, allowing a malicious or compromised registry to cause SSRF to internal networks such as http://169.254.169.254/, http://10.0.0.x/, and http://127.0.0.1/, or to downgrade a registry contacted over https:// to an http:// token endpoint in registry/remote/auth/client.go through Client.Do(), Client.fetchBearerToken(), fetchDistributionToken, and fetchOAuth2Token. This issue is fixed in version 2.6.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | oras.land/oras-go/v2 | all versions | 2.6.1 |
| 🐹Go | oras.land/oras-go | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for oras.land/oras-go/v2. 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 oras.land/oras-go/v2 to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48978 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-2026-48978 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-2026-48978. 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-2026-48978 in your dependencies?
O3 detects CVE-2026-48978 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.