CVE-2026-48021
CRITICALepa4all Security Incident: Implement keystore based on Telematik TSL, implement hostname check and certificate check for lib-vau
Description
In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic (patient consent decisions, medication data, document operations, authorization tokens, and entitlement queries) becomes readable and modifiable. The attacker can also inject arbitrary requests through the hijacked channel. This issue has been patched in version 2026-05-20.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-48021 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-48021 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-2026-48021. 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-2026-48021 in your dependencies?
O3 detects CVE-2026-48021 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.