CVE-2026-100699
Description
A flaw was found in nodemailer. The address parser incorrectly processes email addresses containing quoted local parts followed by comments, allowing trailing domain text to be retained in the normalized address. A remote attacker could supply a crafted recipient address to inject malformed domain data into the Simple Mail Transfer Protocol (SMTP) message envelope, potentially leading to unintended email routing or delivery.
Statement
This vulnerability is rated as Moderate severity because, although an unauthenticated remote actor could submit malformed recipient addresses, the practical impact is limited to unintended routing or SMTP envelope rejection rather than host compromise or information exposure. In standard Red Hat product deployments, shipped components either do not utilize the affected feature branches or embed earlier releases that lack this specific parsing behavior. Applications are only susceptible if they accept unvalidated, user-controlled address strings and feed them directly into the mail delivery pipeline.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
When untrusted input is not properly validated for the expected syntax, attackers could cause parsing failures, trigger unexpected errors, or expose latent vulnerabilities that might not be directly exploitable if the input had conformed to the syntax.
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