Twisted: Unauthenticated Remote Denial Of Service In The Twisted Conch Telnet Transport Via An Unbounded Subnegotiation

Summary An allocation-without-limits vulnerability CWE-770 in the Twisted conch telnet transport lets any unauthenticated remote peer exhaust server memory over a single connection. When the peer opens a telnet subnegotiation with "IAC SB" and then streams bytes without ever sending the "IAC SE"...

GHSA-CWM5-JH59-MWXR Twisted: Unauthenticated Remote Denial of Service in the Twisted conch Telnet Transport via an Unbounded Subnegotiation Buffer

Summary An allocation-without-limits vulnerability CWE-770 in the Twisted conch telnet transport lets any unauthenticated remote peer exhaust server memory over a single connection. When the peer opens a telnet subnegotiation with IAC SB and then streams bytes without ever sending the IAC SE...

CVE-2026-115778 Twisted: Unauthenticated Remote Denial of Service in the Twisted conch Telnet Transport via an Unbounded Subnegotiation Buffer

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.conch.telnet.Telnet.dataReceived appends every byte received after IAC SB to a persistent subnegotiation buffer until IAC SE is received, without applying a maximum length. Telnet...