Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-115778: A flaw was found in Twisted. The Telnet service implementation fails to enforce a size limit on incoming data buffers during protocol option negotiation, which occurs before user authentication. An unauthenticated remote attacker can exploit this vulnerability by sending a continuous stream of subnegotiation data without a terminating delimiter. This causes unbounded memory consumption that can crash the application, resulting in a Denial of Service (DoS). CVE-2026-115776: A flaw was found in Twisted. The Internet Relay Chat (IRC) protocol implementation does not enforce a maximum line length when buffering incoming connection data. An unauthenticated remote attacker can exploit this by sending a continuous stream of data without line feed characters to an IRC service. This causes the server process to consume excessive memory until it runs out of resources, resulting in a Denial of Service (DoS) that terminates connections for all users. CVE-2026-115775: A flaw was found in Twisted. An unauthenticated remote attacker can cause a Denial of Service (DoS) by exhausting server memory. The issue occurs because the XML stream parser retains unfinished elements in memory without enforcing size or element count limits. By transmitting a continuous stream of child elements within an unclosed container during pre-authentication communication, an attacker can crash the server process.
Fixed packages 2
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | python3-twisted | 0:22.4.0-129.amzn2023.0.7 |
| Amazon Linux · 2023 | python3-twisted+tls | 0:22.4.0-129.amzn2023.0.7 |
Vulnerabilities 3
-
High 8.7
Twisted: Unauthenticated Remote Denial of Service in the Twisted words domish XML Element Stream via an Unbounded Element Tree
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, the twisted.words.xish.domish ExpatElementStream parser allows an unauthenticated remote peer to keep a container element open while continuously addin…
-
High 7.5
Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.words.protocols.irc.IRC.dataReceived retains all bytes received without a line feed in its per-connection buffer and applies no maximum line le…
-
High 7.5
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, witho…