Vulnerability in Badkeys
CVE-2026-21439
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (24.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: -0.000
Affected products
- Badkeys — versions < 0.0.16
Weakness classification (CWE)
References
- github.com/badkeys/badkeys/security/advisories/GHSA-wjpc-4f29-83h3 (Third Party Advisory)
- github.com/badkeys/badkeys/issues/40 (Exploit, Third Party Advisory, Issue Tracking)
- github.com/badkeys/badkeys/commit/635a2f3b1b50a895d8b09ec8629efc06189f349a (Patch)
- github.com/badkeys/badkeys/commit/de631f69f040974bb5fb442cdab9a1d904c64087 (Patch)
Frequently asked questions
- What is CVE-2026-21439?
- CVE-2026-21439 is a medium-severity vulnerability in Badkeys, classified under CWE-150. CVSS score: 5.3/10. Published 2026-01-06.
- How severe is CVE-2026-21439?
- Medium severity. CVSS v3 base score is 5.3 out of 10.