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

影響: pip:Twisted <= 26.4.0 → 26.10.0rc1

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 terminator, every byte is appended to a per-connection buffer that has no maximum length. The buffer persists across reads and is released only on the terminator the attacker withholds, so it grows without bound…

Read on GitHub Advisory Database

On 10/24/2026, 05:45 AM, GitHub Advisory Database published "Twisted: Unauthenticated Remote Denial of Service in the Twisted conch Telnet Transport via an Unbounded Subnegotiation Buffer" (type: Advisory). Severity is "High" (high). Related technologies: Python. CVE: CVE-2026-115778.