CVE-2026-128089

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-11-12 21:24 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-13 20:18 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-13 20:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: not scored yet.
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-13 20:18 UTC

Last modified

2026-11-13 20:18 UTC

Weakness

CWE-400 · Uncontrolled resource consumption

Record status

Received

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-128089.md and follow it. Check whether this project is affected by CVE-2026-128089. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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