CVE-2026-121946
High
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.
SeverityHigh
CVSS7.2
Exploit probability—
ProductZbateson Mail-mime-parser
PublishedNov 4, 2026
First seenNov 4, 2026
Weakness typeCWE-93CWE-93
How to fix
Update
- zbateson mail-mime-parser3.0.9, 4.0.6 or later
Patches
- github.com/zbateson/mail-mime-parser/commit/f385b2923023a9a7b69003468e363a4661f1c85a
- github.com/zbateson/mail-mime-parser/commit/1fa840ef367958e991e6840b4e3ffd41aca9d147
- github.com/zbateson/mail-mime-parser/commit/c31c62ccc3e66a7a7da0d79954ef83807f9daa20
- github.com/zbateson/mail-mime-parser/commit/b032920875c6cb35bb2ddd7abfd7e98608d75bc0
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| zbateson mail-mime-parser | No range specified, 4.x ≤ v | 3.0.9, 4.0.6 |
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