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 option negotiation occurs before authentication, so an unauthenticated peer can omit the terminator and continuously grow the buffer. The resulting memory exhaustion can terminate the process and every service it hosts. This issue is fixed in version 26.10.0rc1.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:5215-1 advisory.

    - CVE-2026-83813: DNS spoofing in `twisted.names` due to missing source address validation (bsc#1287833).
    - CVE-2026-106454: ReDoS due to improper use of `re.compile()` in `wildcardToRegexp()` (bsc#1284420).
    - CVE-2026-115774: denial of service via negative size in IMAP search command (bsc#1287671).
    - CVE-2026-115775: denial of service via memory exhaustion in XML stream parser (bsc#1287675).
    - CVE-2026-115776: denial of service via unbounded IRC buffer (bsc#1287676).
    - CVE-2026-115778: denial of service via memory exhaustion during Telnet negotiation (bsc#1287678).
    - CVE-2026-115877: HTTP request smuggling due to improper header delimiter handling (bsc#1287848).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3385 advisory.

    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. (CVE-2026-115775)

    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-2026-115776)

    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-2026-115778)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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
    option negotiation occurs before authentication, so an unauthenticated peer can omit the terminator and
    continuously grow the buffer. The resulting memory exhaustion can terminate the process and every service
    it hosts. This issue is fixed in version 26.10.0rc1. (CVE-2026-115778)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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     option negotiation occurs before authentication, so an unauthenticated peer can omit the terminator and     continuously grow the buffer. The resulting memory exhaustion can terminate the process and every service     it hosts. This issue is fixed in version 26.10.0rc1. (CVE-2026-115778)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
381002	SUSE SLED15: python311-Twisted / python311-Twisted-all_non_platform / etc (SUSE-SU-2026:5215-1)	Nessus	SuSE Local Security Checks	Local	high
377965	Amazon Linux 2023 : python3-twisted, python3-twisted+tls (ALAS2023-2026-3385)	Nessus	Amazon Linux Local Security Checks	Local	high
478041	Chainguard: synapse: security update to 1.164.1-r2	Tenable Cloud Security	Chainguard Local Security Checks	Local	high
478041	Chainguard: synapse: security update to 1.164.1-r2	Tenable Self-Hosted Container Security	Chainguard Local Security Checks	Local	high
477240	SCA: security update for Twisted (GHSA-cwm5-jh59-mwxr)	Tenable Cloud Security	SCA Checks	Local	high
477240	SCA: security update for Twisted (GHSA-cwm5-jh59-mwxr)	Tenable Self-Hosted Container Security	SCA Checks	Local	high
371718	Linux Distros Unpatched Vulnerability : CVE-2026-115778	Nessus	Misc.	Local	high

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