NVD / CVE Program· CNA VulnCheck

CVE-2026-92596: Nodemailer before 9.1.0 Denial of Service via addressparser

Noroxi assessment

Priority: Monitor (action score 34/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.82% (FIRST EPSS); higher than 57.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: nodemailer nodemailer 9.1.0.

Low priority for now. Upgrade to nodemailer nodemailer 9.1.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Nodemailer before 9.1.0 contains a quadratic time complexity vulnerability in the addressparser component that allows remote attackers to cause denial of service by supplying a crafted comma-separated address list. Attackers can send a single email with a large number of addresses to block the Node.js event loop for extended periods, consuming 100% CPU and freezing the process.

HighCVSS 8.7 · v4.0—No exploit Fix available

Published: Sep 16, 2026
Updated: Sep 22, 2026
EPSS: 0.8% · 57th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.8%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · VulnCheck: 8.7; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

nodemailer nodemailer
- 9.1.0not affected
- before 9.1.0affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	node-nodemailer	from 0	—
Debian:14	node-nodemailer	before 10.0.0+~8.0.1-1	10.0.0+~8.0.1-1
npm	nodemailer	before 9.1.0	9.1.0

Same product

nodemailer: all records

Other highest-scoring records for the same primary product.

CVE-2020-7769This affects the package nodemailer before 6.4.16.
40Plan
CVE-2026-82854Nodemailer before 8.0.4 SMTP Command Injection via envelope.size
38Monitor
CVE-2021-23400HTTP Header Injection
35Monitor

Published before and after this one in the same product

← EarlierCVE-2026-90776Sep 13, 2026 · Nodemailer 9.1.0 through 10.0.4 Denial of Service via Quadratic Address Parsing
34Monitor
← EarlierCVE-2026-92595Sep 16, 2026 · Nodemailer before 9.1.1 Security Sandbox Bypass via resolveContent
24Monitor
Later →CVE-2026-92597Sep 16, 2026 · Nodemailer before 9.1.0 Email Domain Validation Bypass via RFC 5322 Comment
33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
nodemailer nodemailer	9.1.0	Vendor (CNA)
debian:node-nodemailer	10.0.0+~8.0.1-1 · Debian:14	Package registry (OSV)
npm:nodemailer	9.1.0	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

e1abradorreporter

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-11087228 days apartNodemailer 3.0.0 before 10.0.10 Denial of Service via SMTP Reply Parsing
32Monitor
CVE-2026-11087128 days apartNodemailer 3.0.0 before 10.0.10 Quadratic DKIM Header Unfolding Denial of Service
28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/nodemailer/nodemailer/commit/34da642

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records