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Fencer Intel
medium 4.3

CVE-2026-106454 json

Twisted: IMAP wildcardToRegexp() ReDoS

published last mo. modified 25d ago also EUVD-2026-93873 , GHSA-8pqf-f4m5-798g , PYSEC-2026-4304

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

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 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.

Patch / fix

  • twisted Debian 14 26.4.0-5

debian advisories DEBIAN-CVE-2026-106454

  • twisted Ubuntu 22.04 LTS 22.1.0-2ubuntu2.8
  • twisted Ubuntu 24.04 LTS 24.3.0-1ubuntu0.3
  • twisted Ubuntu 26.10 26.4.0-4ubuntu0.1
  • twisted Ubuntu 26.04 LTS 25.5.0-5ubuntu0.2

ubuntu advisories UBUNTU-CVE-2026-106454

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-Twisted openSUSE Tumbleweed 26.4.0-4.1

opensuse advisories openSUSE-SU-2026:12137-1

  • python-twisted Azure Linux 3.0 22.10.0-7

azure linux advisories AZL-106712

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-106454 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-106454 updated cvss 4.3

twisted: Twisted: Denial of Service via regular expression backtracking in IMAP search patterns

  • Red Hat Ansible Automation Platform 2 python-twisted 23.10.0-1.el9ap, python3x-twisted 23.10.0-1.el8ap, python3.11-twisted 24.7.0-1.el9ap, python3.12-twisted 24.7.0-2.el9ap, automation-controller 4.7.17-1.el9ap, ansible-automation-platform-24/controller-rhel8, +10 more
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat OpenShift Container Platform 4 openshift4/ose-kuryr-cni-rhel8, openshift4/ose-kuryr-controller-rhel8
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenStack Platform 16.2 python3-twisted, python-twisted 23.10.0-1.el9ap
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Hardened Images python-jsonschema 4.26.0-10.1.hum1
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/twisted/twisted/security/advisories/GHSA-8pqf-f4m5-798g referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
pypi twisted
<=26.4.0
<=25.5.0
 no fix listed

Affected products

  • twisted twisted

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.