Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
High, CVSS 7.5amended

Nodemailer: Quadratic (O(n²)) time complexity in addressparser allows remote denial of service via a crafted address list

CVE-2026-92596GHSA-2x7j-588g-ccc2

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (nodemailer 9.1.0), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
  • CVE-2026-92596: 0.82% estimated exploitation activity in the next 30 days; percentile 57.43 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Summary Nodemailer's address parser (lib/addressparser/index.js) parses a list of comma‑separated addresses in quadratic time — O(n²) in the number of addresses. A single crafted address string (e.g. a To, Cc, Bcc, From, or Reply‑To value, or any value passed to the exported addressparser) therefore consumes CPU proportional to the square of its length and blocks Node's single‑threaded event loop for the entire duration, denying service to every other request in the process. This requires no special application configuration and no cooperating receiver — it is entirely inside the parser and triggers on the library's default code path. A ~1.5 MB address value freezes the process for ~25–30 seconds of 100% CPU; the cost grows with the square of the input, so a few‑MB value stalls the server for minutes. It is a distinct issue from the recursion DoS fixed as CVE‑2025‑14874 (that path is guarded by a nesting‑depth cap; this one is a flat, comma‑separated list with no such limit). Details…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-2x7j-588g-ccc2

  2. Revision 2 · amended ·

    Amended from osv record GHSA-2x7j-588g-ccc2

  3. Revision 1 · created ·

    Published from ghsa record GHSA-2x7j-588g-ccc2

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-92596

Advisory: Nodemailer: Quadratic (O(n²)) time complexity in addressparser allows remote denial of service via a crafted address list
IDs: CVE-2026-92596, GHSA-2x7j-588g-ccc2
Record: https://patchnext.com/advisories/ghsa-2x7j-588g-ccc2 (revision 3, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nodemailer 9.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm nodemailer: affected < 9.1.0; fixed in 9.1.0

## Suggested inspection (read-only)
- `npm ls nodemailer --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nodemailer.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2x7j-588g-ccc2 (GitHub-reviewed advisory GHSA-2x7j-588g-ccc2 lists affected ranges: npm nodemailer >=0 <9.1.0)
- Verified: https://osv.dev/vulnerability/GHSA-2x7j-588g-ccc2 (OSV record GHSA-2x7j-588g-ccc2 lists affected ranges: npm nodemailer >=0 <9.1.0 (fixed))

Commands are suggestions: review each one before running it.

Loading voting…