Node nodemailer: Nodemailer from 3.0.0 before 10.0.10 contains a quadratic complexity denial of service vulnerability
Affects node-nodemailerSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 28 Oct 2026, 23:57 UTC
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10node-nodemailerpkg:deb/ubuntu/node-nodemailer?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSnode-nodemailerpkg:deb/ubuntu/node-nodemailer?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSnode-nodemailerpkg:deb/ubuntu/node-nodemailer?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSnode-nodemailerpkg:deb/ubuntu/node-nodemailer?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSnode-nodemailerpkg:deb/ubuntu/node-nodemailer?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is applied, avoid connecting to untrusted SMTP servers or mitigate exposure by network controls.
Description
Nodemailer versions from 3.0.0 up to but not including 10.0.10 contain a denial of service vulnerability due to quadratic complexity in the SMTP client reply parser. This flaw allows a malicious SMTP server or an attacker in the network path to send specially crafted continuation lines without a completion line before authentication, causing the Node.js event loop to block and memory to be exhausted.
References
- ubuntu.com/security/CVE-2026-110872 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-110872 (opens in a new tab)
- github.com/nodemailer/nodemailer/security/advisories/GHSA-4g23-2xm8-66gc (opens in a new tab)
- vulncheck.com/advisories/nodemailer-3.0.0-before-10.0.10-denial-of-service-via-smtp-reply-parsing (opens in a new tab)