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Vulnerabilities

Vulnerability · CVE-2026-42304

Twisted is an event-based framework for internet applications, supporting Python 3.6+.

Published May 13, 2026 · catalog updated Jun 17, 2026 · Twisted is an event-based

Check if you run it

No confirmed exploitation is on record for CVE-2026-42304. EPSS is 0.95%. Act only if a listed version of Twisted is an event-based is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Twisted is an event-based).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.95%
Remediation
Advisory link
Affected products
cpe twisted/twisted

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous loop-prevention logic, causing the single-threaded Twisted reactor to hang while processing millions of recursive lookups, effectively freezing the server. This vulnerability is fixed in 26.4.0rc2.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe twisted/twisted26.4.0

How to fix CVE-2026-42304

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-42304. EPSS is 0.95%. Act only if a listed version of Twisted is an event-based is installed.

Which versions are affected?

Compare what you have installed with 26.4.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption; CWE-407. EPSS 0.95%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 13, 2026 · NIST NVD

    Detected

    Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous

  2. Jun 17, 2026 · NIST NVD

    Updated

    Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous

Sources

  • CVE.orgVulnerability recordCVE-2026-42304

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-42304

    30-day exploitation probability 0.9%

    first.org
  • NIST NVDVulnerability recordCVE-2026-42304

    Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can expl

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.