nodemailer ReDoS when trying to send a specially crafted email

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

• CVE-2024-58379: 0.42% estimated exploitation activity in the next 30 days; percentile 36.17 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A ReDoS vulnerability occurs when nodemailer tries to parse img files with the parameter attachDataUrls set, causing the stuck of event loop. Another flaw was found when nodemailer tries to parse an attachments with a embedded file, causing the stuck of event loop. Details Regex: /^data:((?:[^;];)(?:[^,])),(.)$/ Path: compile - getAttachments - processDataUrl Regex: /(<img\b[^] src\s=[\s"'])(data:([^;]+);[^"'\s]+)/ Path: convertDataImages PoC https://gist.github.com/francoatmega/890dd5053375333e40c6fdbcc8c58df6 https://gist.github.com/francoatmega/9aab042b0b24968d7b7039818e8b2698 Impact ReDoS causes the event loop to stuck a specially crafted evil email can cause this problem.

Published by the source

31 Jan 2024, 22:42 UTC

Last modified by the source

1 Sep 2026, 03:55 UTC

Source last checked

26 Oct 2026, 12:37 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-9h6g-pr28-7cqp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-9h6g-pr28-7cqp

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# Patch Next advisory brief: CVE-2024-58379

Advisory: nodemailer ReDoS when trying to send a specially crafted email
IDs: CVE-2024-58379, GHSA-9h6g-pr28-7cqp
Record: https://patchnext.com/advisories/cve-2024-58379 (revision 2, source checked 26 Oct 2026, 12:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nodemailer 6.9.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm nodemailer: affected <= 6.9.8; fixed in 6.9.9

## 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://osv.dev/vulnerability/GHSA-9h6g-pr28-7cqp (OSV record GHSA-9h6g-pr28-7cqp lists affected ranges: npm nodemailer >=0 <6.9.9 (fixed))
- Verified: https://github.com/advisories/GHSA-9h6g-pr28-7cqp (GitHub-reviewed advisory GHSA-9h6g-pr28-7cqp lists affected ranges: npm nodemailer >=0 <=6.9.8)

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