CVE-2026-128089

dnspython excessive memory and CPU use

Published Nov 13, 2026 CVSS 3.1 · 7.5 High EPSS n/a KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
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.
Title dnspython excessive memory and CPU use
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'}

Subscriptions

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Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 13, 2026, 7:22 PM
Reserved
Nov 12, 2026, 9:24 PM

No data.