CVE-2026-21439
Medium
Description
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.
SeverityMedium
CVSS5.3
Exploit probability—
ProductBadkeys
PublishedJan 6, 2026
First seenJan 6, 2026
Weakness typeCWE-150CWE-150
How to fix
Update
- badkeys badkeys0.0.16 or later
- badkeys0.0.16 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| badkeys badkeys | v < 0.0.16 | 0.0.16 |
| badkeysPyPI | v < 0.0.16 | 0.0.16 |
Check your version
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