CVE-2026-100699
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated domain atoms to be retained in the normalized address. For example, the input "user"@example.com(x)evil.com is parsed to the address value '[email protected] evil.com', which contains additional attacker-controlled domain text separated by a literal space. This parsed value is used without further strict recipient validation when the message envelope is built (envelope.to in src/mime-node), so a malformed/ambiguous recipient address can be accepted and placed in the SMTP envelope. Whether this results in delivery to an unintended recipient on real SMTP servers has not been confirmed. The issue is a variant of the RFC 5322 comment parsing problem addressed in GHSA-cc9r-2j5m-2m83, affecting the separate quoted-local-part code path. Version 10.0.9 contains a fix.
Risk Assessment
Risk includes the possibility of sending emails to unintended recipients due to incorrect address parsing, which can lead to confidentiality breach or delivery to the wrong person.
Recommendation
Update Nodemailer to version 10.0.9 or later, which fixes the vulnerability.
Other vulnerabilities in Nodemailer
See all- GHSA-wmmp-3585-3rmpMedium
Nodemailer resolves an international (IDN / non-ASCII) recipient domain to a different Punycode label than every UTS-46-conformant parser (web browsers, WHATWG URL Standard, Node's url.domainToASCII, Python's idna). Its address normalizer (_normalizeAddress) may lead to incorrect domain resolution, enabling phishing or message misdirection.
- GHSA-2x7j-588g-ccc2High
Nodemailer's address parser parses comma-separated addresses in quadratic time (O(n²)) in the number of addresses. A single crafted address string (e.g., To, Cc, Bcc, From, Reply-To) can cause significant slowdown.
- GHSA-cc9r-2j5m-2m83Medium
Nodemailer's email-address parser treats an RFC 5322 comment inside the domain as a point to concatenate the surrounding text, rather than as folding whitespace (CFWS) that terminates the domain. This can lead to incorrect parsing, e.g., [email protected](x)evil.c..., potentially redirecting messages or bypassing validation.
- GHSA-8m3c-c648-2xjjMedium
Nodemailer's disableFileAccess/disableUrlAccess options are a security sandbox that forbids untrusted message content from reading local files or making outbound HTTP(S) requests. The fix for GHSA-wqvq-jvpq-h66f may be incomplete, allowing bypass of the sandbox.
- GHSA-r7g4-qg5f-qqm2Medium
Nodemailer disables TLS certificate verification in its internal HTTPS fetch client by setting rejectUnauthorized: false in lib/fetch/index.js. This causes OAuth2 token requests to trust invalid or self-signed HTTPS certificates.
- GHSA-8vvx-rff5-p5rqMedium
A vulnerability exists in the nodemailer package (npm) affecting versions from 2.7.2 to 10.0.1. Details are not fully described in the provided snippet, but vulnerable versions are confirmed.
- GHSA-268h-hp4c-crq3Medium
A vulnerability in the Nodemailer library allows header injection via the `list.*.comment` field, which is not sanitized for CR (`\r`) and LF (`\n`) characters. An attacker can supply a malicious value in this field, leading to email header spoofing.
- GHSA-p6gq-j5cr-w38fHigh
In nodemailer v9.0.0, the message-level `raw` option bypasses `disableFileAccess` and `disableUrlAccess` protections, enabling arbitrary file reads and full SSRF (Server-Side Request Forgery) in the sent message.
- GHSA-wqvq-jvpq-h66fMedium
A vulnerability in Nodemailer allows bypassing the `disableFileAccess` and `disableUrlAccess` options when using `jsonTransport`. While the normal MIME streaming path enforces these restrictions, `jsonTransport` serializes the message in a way that bypasses them, potentially enabling access to local files or external URLs.
- GHSA-6vj9-mwq6-2f5vMedium
Nodemailer's process-global DNS cache is keyed only by `host`, but each cache entry also stores the caller-specific TLS `servername`. When two direct SMTPS transports use the same DNS host with different `tls.servername` values, the first transport's server name is returned to the second.
Original NVD description (English source)
Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated domain atoms to be retained in the normalized address. For example, the input "user"@example.com(x)evil.com is parsed to the address value '[email protected] evil.com', which contains additional attacker-controlled domain text separated by a literal space. This parsed value is used without further strict recipient validation when the message envelope is built (envelope.to in src/mime-node), so a malformed/ambiguous recipient address can be accepted and placed in the SMTP envelope. Whether this results in delivery to an unintended recipient on real SMTP servers has not been confirmed. The issue is a variant of the RFC 5322 comment parsing problem addressed in GHSA-cc9r-2j5m-2m83, affecting the separate quoted-local-part code path. Version 10.0.9 contains a fix.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS