CVE-2026-48816 is a medium-severity (CVSS 6.5) CWE-345 vulnerability in @sigstore/verify. O3 Security confirms whether CVE-2026-48816 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
sigstore-js: Insufficient Verification of Data Authenticity
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@sigstore/verifynpmDescription
sigstore-js provides JavaScript libraries for interacting with Sigstore services. Prior to 3.1.1, @sigstore/verify derives a transparency-log timestamp from tlogEntries[].integratedTime for bundle v0.2 inclusionProof-only entries even though the inclusion proof path does not cryptographically bind integratedTime, allowing an attacker who can supply an untrusted bundle to influence certificate validity and timestampThreshold verification decisions. This issue is fixed in version 3.1.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @sigstore/verify | ≥ 3.1.0&&< 3.1.1 | 3.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sigstore/verify. 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 @sigstore/verify to 3.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48816 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-2026-48816 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-2026-48816. 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-2026-48816 in your dependencies?
O3 detects CVE-2026-48816 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.