---
id: CVE-2026-106454
title: >-
  Twisted is an event-based framework for internet applications, supporting
  Python 3.6+
summary: >-
  Twisted is an event-based framework for internet applications, supporting
  Python 3.6+. In 25.5.0 and earlier, wildcardToRegexp() in
  twisted/mail/imap4.py translates the IMAP asterisk and percent wildcards but
  passes all other characters …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-1333
vendor: twisted
product: twisted
affected:
  - twisted <= 25.5.0
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T20:17:27.597'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106454'
references:
  - url: >-
      https://github.com/twisted/twisted/commit/2f8a3c29246f4eb324690e06a9767a11dc4aec9f
    label: security-advisories@github.com
  - url: 'https://github.com/twisted/twisted/pull/12788'
    label: security-advisories@github.com
  - url: 'https://github.com/twisted/twisted/security/advisories/GHSA-8pqf-f4m5-798g'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-06T20:16:42.469Z'
---

## Overview

Twisted is an event-based framework for internet applications, supporting Python 3.6+. In 25.5.0 and earlier, wildcardToRegexp() in twisted/mail/imap4.py translates the IMAP asterisk and percent wildcards but passes all other characters from an authenticated client's LIST or LSUB pattern directly to re.compile(), allowing nested or otherwise expensive regular expression constructs to cause catastrophic backtracking when matched against mailbox names. Because Twisted uses a cooperative single-threaded reactor, the blocking match suspends all server input and output for the duration of the match. No fixed release is available as of this review.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.