CVE-2026-115778: DoS (CVSS 7.5)

Description

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.

Is your site exposed to CVE-2026-115778?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption

CWE-770 CWE-770

References

Other References

https://github.com/twisted/twisted/commit/073ba878c6c07d569cb61abc5ae76d46eff1b529 https://github.com/twisted/twisted/commit/5d91cc66a3591faba758a80a1479e0103602facc https://github.com/twisted/twisted/pull/12750 https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1 https://github.com/twisted/twisted/security/advisories/GHSA-cwm5-jh59-mwxr

Frequently Asked Questions

What is CVE-2026-115778? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-115778? +

CVE-2026-115778 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2026-115778? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-45802

FPDI is a collection of PHP classes that facilitate reading pages from existing PDF documents and using them as templates …

CVE-2026-101911

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. Prior to 10.7.1, the Address6 constructor, …

CVE-2026-67318

axios versions >=1.13.0 (Node.js HTTP adapter) fail to enforce the configured maxBodyLength limit on streamed request bodies when requests are …

CVE-2026-42343

FastGPT is an AI Agent building platform. In versions 4.14.13 and prior, the code-sandbox component suffers from insufficient resource isolation …

CVE-2026-66071

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom …

CVE-2026-67226

RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7, Admin-only atom exhaustion: PUT /api/users …

CVE-2026-115778