CVE-2026-35191

/// Technical description

Issue summary: The OpenSSL QUIC server, when configured to not preform address

validation, can be forced to count incoming packets multiple times in its

unvalidated credit computation, leading to a violation of the RFC 9000

unvalidated connection amplification limit of 3 times the amount of data

received.

Impact summary: A remote attacker able to spoof packets to a server using the

OpenSSL QUIC implementation might use the server for an amplification of

a DDoS attack.

CWE: CWE-440: Expected Behavior Violation

Description: OpenSSL's QUIC stack, when operating as a server, enforces client

address validation (RFC 9000, Section 8), to confirm the peer address is not

used for a traffic amplification attack. If this feature is disabled on the

server, the QUIC stack limits the amount of server data that can be sent to 3

times the amount of data received from the peer address, until such time as the

TLS handshake is completed.

The OpenSSL QUIC server, when operating in non-validation mod

/// Remediation

Check the references section for vendor advisories and patches from openssl. Update openssl to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// Affected products

/// References