CVE-2026-93564 is a vulnerability in HAProxy's PROXY-v2 protocol handling where an incomplete fix for a previous issue leads to a ByteBuf reference-count leak in nested TLV grandchild structures. This flaw can cause a denial of service due to resource exhaustion. The vulnerability has a high severity rating with a CVSS score of 7.5. A Red Hat advisory references this issue in the context of their Quarkus build, indicating that security updates are available.