CVE-2026-63652
Fix: FreeRDP/FreeRDP@caf653cCVE-2026-63652 is a CWE-415 vulnerability. O3 Security confirms whether CVE-2026-63652 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, rdpsnd_server_recv_formats in channels/rdpsnd/server/rdpsnd_main.c frees context->client_formats on…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-63652.
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, rdpsnd_server_recv_formats in channels/rdpsnd/server/rdpsnd_main.c frees context->client_formats on a malformed Client Audio Formats PDU without clearing the owning pointer or num_client_formats. An authenticated RDP client can trigger an error such as a cbSize larger than the remaining record, leave the dangling pointer in the server context, and cause rdpsnd_server_context_free to free the same allocation again at session teardown. This reliably terminates the server and can create allocator-dependent heap corruption. This issue is fixed in version 3.28.0.
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-2026-63652 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-2026-63652 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-2026-63652. 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-2026-63652 in your dependencies?
O3 detects CVE-2026-63652 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.