CVE-2026-121946

HIGHCVSS 7.2/10

Last modified

CVE-2026-121946 is a high-severity vulnerability rated 7.2/10 on the CVSS scale. 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..

Description

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
zbatesonmail-mime-parser>= 0.3.0, < 3.0.9; >= 4.0.0, < 4.0.6

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-121946?
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.
How severe is CVE-2026-121946?
CVE-2026-121946 has a CVSS score of 7.2/10 (HIGH severity).
How do I fix CVE-2026-121946?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST