CVE-2026-50577 is a high-severity (CVSS 7.4) CWE-323 vulnerability. O3 Security confirms whether CVE-2026-50577 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration leaves request_counter…
Description
ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration leaves request_counter unchanged in app/vau/VAUProtokoll.py while constructing VAU messages. The frozen client request counter causes the server side to reuse AES-GCM nonce and key combinations across responses. A network attacker who collects repeated ciphertexts can recover the XOR of plaintexts and use predictable inner HTTP headers and JSON fields to recover sensitive data, including patient health records. Repeated nonces can also enable recovery of the GHASH authentication key through the Joux forbidden attack, allowing forged AES-GCM messages and injection of malicious responses. The response-counter check also fails to maintain last_response_counter, weakening replay and ordering validation. This issue is fixed in version 1.3.0.
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-2026-50577 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-2026-50577 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-2026-50577. 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-2026-50577 in your dependencies?
O3 detects CVE-2026-50577 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.