PatchTheCVECVE-2026-121946: zbateson mail-mime-parser before 3.0.9 and 4.x before 4.0.6 contains a CRLF header injection vulnerability in
CVE-2026-121946 is a high-severity flaw (CVSS 7.2) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
zbateson mail-mime-parser before 3.0.9 and 4.x before 4.0.6 contains a CRLF header injection vulnerability in message-building helpers that fail to strip CR and LF characters. Attackers supplying crafted MIME type, charset, encoding, micalg, or protocol values can inject extra header lines such as a forged Bcc into outgoing messages.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 7.2 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-93 |
| Published | 2026-11-04 |
| Last modified | 2026-11-04 |
Last updated 2026-11-04 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- VulDB Recent Entries: CVE-2026-121946 | zbateson mail-mime-parser up to 3.0.8/4.0.5 Message-Building Helpers crlf injection (EUVD-2026-116903) 2026-11-04
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-121946?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-121946 being exploited?
CVE-2026-121946 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-121946 affect?
CVE-2026-121946 affects affected software. Severity is high (CVSS 7.2). zbateson mail-mime-parser before 3.0.9 and 4.x before 4.0.6 contains a CRLF header injection vulnerability in message-building helpers that fail to strip CR and LF characters. Attackers supplying crafted MIME type, charset, encoding, micalg
How urgent is CVE-2026-121946?
Priority 30/100. High severity; Remotely exploitable, no login, no user action