badkeys up to 0.0.15 ANSI Escape Sequence control sequence

Summaryinfo

A vulnerability classified as problematic was found in badkeys up to 0.0.15. Affected by this issue is some unknown functionality of the component ANSI Escape Sequence Handler. Such manipulation leads to control sequence. This vulnerability is documented as CVE-2026-21439. The attack needs to be performed locally. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in badkeys up to 0.0.15. Affected by this issue is an unknown function of the component ANSI Escape Sequence Handler. The manipulation with an unknown input leads to a control sequence vulnerability. Using CWE to declare the problem leads to CWE-150. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component. Impacted is integrity. CVE summarizes:

badkeys is a tool and library for checking cryptographic public keys for known vulnerabilities. In versions 0.0.15 and below, an attacker may inject content with ASCII control characters like vertical tabs, ANSI escape sequences, etc., that can create misleading output of the badkeys command-line tool. This impacts scanning DKIM keys (both --dkim and --dkim-dns), SSH keys (--ssh-lines mode), and filenames in various modes. This issue is fixed in version 0.0.16.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-21439 since 12/29/2025. The exploitation is known to be easy. Local access is required to approach this attack. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

Upgrading to version 0.0.16 eliminates this vulnerability. Applying the patch 635a2f3b1b50a895d8b09ec8629efc06189f349a is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202601-954). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• badkeys

Version

• 0.0.1
• 0.0.2
• 0.0.3
• 0.0.4
• 0.0.5
• 0.0.6
• 0.0.7
• 0.0.8
• 0.0.9
• 0.0.10
• 0.0.11
• 0.0.12
• 0.0.13
• 0.0.14
• 0.0.15

License

• open-source

Website

• Product: https://github.com/badkeys/badkeys/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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