CVE-2026-55558: Asyncio Starttls Unpurged Buffer Injection

Calling `start_tls` without first clearing the protocol's internal receive buffer allows unencrypted data injected by a network attacker prior to the TLS handshake to persist and be processed as authentic data within the encrypted TLS session (STARTTLS injection). Ensure any buffered plaintext bytes are purged (e.g., `del self._buffer[:]` or `self._buffer.cl

Provally CuratedPublic repositoryMediumMedium confidenceVerifiedApache-2.0Python
greprules fetch cve-2026-55558-asyncio-starttls-unpurged-buffer-injection --engine opengrep

Description

Calling `start_tls` without first clearing the protocol's internal receive buffer allows unencrypted data injected by a network attacker prior to the TLS handshake to persist and be processed as authentic data within the encrypted TLS session (STARTTLS injection). Ensure any buffered plaintext bytes are purged (e.g., `del self._buffer[:]` or `self._buffer.cl