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No exploitation reportedFix availableAwaiting NVD analysis

CVE-2026-128089

dnspython excessive memory and CPU use

No exploitation reported by the sources we read.

  • Published2026-11-13
  • Fixed in2.9.2
  • WeaknessCWE-400 · CWE-770

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

dnspython is a DNS toolkit for Python. Prior to version 2.9.2, the from_text() parser for WKS records does not require the service number to be between 0 and 65535 before using it as a bitmap offset. An attacker-controlled zone file can supply a larger number, causing the service bitmap to grow to an extremely large size through inefficient repeated extension, consuming excessive memory and CPU and potentially terminating the process. Applications are affected only when they parse zone-file text whose record type and rdata are attacker controlled. This issue is fixed in version 2.9.2.

Timeline

dates in UTC
  1. 2026-11-1319:22CVE publishedCNA

Versions per branch

OSV
dnspython
BranchAffectedFixed in
2.9< 2.9.22.9.2

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • rthalley dnspython
    Affected
    • = < 2.9.2no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-13

Fix

  1. Update dnspython to 2.9.2

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 3.17.52026-11-13
  • CNAweakness (CWE)CWE-400, CWE-7702026-11-13
  • NVDweakness (CWE)CWE-400, CWE-770read 2026-11-13
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryHIGH2026-11-13

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-11-13
Last Modified
2026-11-13
NVD status
Received
GitHub Advisory
GHSA-vvf4-9x63-8xvv

Frequently asked questions

What is CVE-2026-128089?

dnspython is a DNS toolkit for Python. Prior to version 2.9.2, the from_text() parser for WKS records does not require the service number to be between 0 and 65535 before using it as a bitmap offset. An attacker-controlled zone file can supply a larger number, causing the service bitmap to grow to an extremely large size through inefficient repeated extension, consuming excessive memory and CPU and potentially terminating the process. Applications are affected only when they parse zone-file text whose record type and rdata are attacker controlled. This issue is fixed in version 2.9.2.

Is CVE-2026-128089 actively exploited?

Active exploitation of CVE-2026-128089 has not been confirmed.

What is the CVSS score for CVE-2026-128089?

CVE-2026-128089 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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