CVE-2026-115776

Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer

Published Oct 23, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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 length. The twisted.words.service.IRCUser server subclass inherits this behavior, and buffering occurs before PASS, NICK, or USER authentication commands. An unauthenticated connection can continuously grow the buffer until the shared server process runs out of memory and drops all users. This issue is fixed in version 26.10.0rc1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-53xc-49m8-p798 Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Twisted
Twisted twisted
Vendors & Products Twisted
Twisted twisted
Type Values Removed Values Added
Description 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 length. The twisted.words.service.IRCUser server subclass inherits this behavior, and buffering occurs before PASS, NICK, or USER authentication commands. An unauthenticated connection can continuously grow the buffer until the shared server process runs out of memory and drops all users. This issue is fixed in version 26.10.0rc1.
Title Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer
Weaknesses CWE-400
CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 30, 2026, 2:27 PM
Reserved
Oct 23, 2026, 1:28 PM
Status
Awaiting Analysis
Published
Oct 23, 2026, 9:17 PM
Modified
Oct 30, 2026, 3:16 PM
Severity
Important
Public date
Oct 23, 2026, 8:18 PM