CVE-2026-82661: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-2jv2-wqrj-g6x7
Share
CVSS 5.4
CWE-93
Published
Advisory Summary

CVE-2026-82661 is a MODERATE (CVSS 5.4) security vulnerability vulnerability (CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product uses crlf (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes crlf sequences from inputs.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-82661 at a Glance

CVE Identifier CVE-2026-82661
GHSA Identifier GHSA-2jv2-wqrj-g6x7
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-82661

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-82661, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & RFC 5280 Specification

Under RFC 5280 specifications for X.509 certificates, the Name Constraints extension defines a namespace within which all subsequent subject names in a certification path must be located. Constraints apply to various name forms including directory names, IP addresses, rfc822Name (email addresses), and uniformResourceIdentifier (URI) entries. Specifically, during certificate path validation, affected versions of Software failed to properly normalize or enforce boundary checks when domain names contained trailing dot (.) characters. Because domain names with a trailing dot signify fully qualified domain names (FQDNs), this omission allowed non-conforming certificates to be improperly validated as compliant with the defined name constraints.

Source Advisory Statement

Nodemailer before 8.0.9 fails to sanitize carriage return and line feed characters in list comment fields, allowing attackers to inject arbitrary message headers. An attacker with control over list.*.comment parameters can inject CRLF sequences to create additional headers in generated RFC822 messages, altering mail client behavior and message semantics.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-268h-hp4c-crq3
NVD — CVE-2026-82661 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-82661
www.vulncheck.com/advisories/nodemail... WEB
https://www.vulncheck.com/advisories/nodemailer-crlf-injection-via-list-header-comments

Frequently Asked Questions

What is CVE-2026-82661?
CVE-2026-82661 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-82661?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-82661?
CVE-2026-82661 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2026-82661?
CVE-2026-82661 is classified under CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') (The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.).
How can I check Maven dependencies for CVE-2026-82661?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2jv2-wqrj-g6x7",
  "modified" : "2026-08-31T09:30:29Z",
  "published" : "2026-08-31T09:30:29Z",
  "aliases" : [ "CVE-2026-82661" ],
  "details" : "Nodemailer before 8.0.9 fails to sanitize carriage return and line feed characters in list comment fields, allowing attackers to inject arbitrary message headers. An attacker with control over list.*.comment parameters can inject CRLF sequences to create additional headers in generated RFC822 messages, altering mail client behavior and message semantics.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nodemailer/nodemailer/security/advisories/GHSA-268h-hp4c-crq3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-82661"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nodemailer-crlf-injection-via-list-header-comments"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-93" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-31T09:17:03Z"
  }
}