High severity · published Sep 26, 2026
CVE-2026-100700
nodemailer before 10.0.6 Denial of Service via addressparser
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
nodemailer before 10.0.6 contains a denial of service vulnerability in the addressparser free-text fallback regex pattern that exhibits quadratic backtracking behavior. Attackers can supply crafted email header values with long whitespace-free runs to block the Node.js event loop for tens of seconds, causing service unavailability.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
nodemailer · nodemailer
before 10.0.6 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-100700
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-100700
vendor-advisory
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-v53p-9fqp-m79j
third-party-advisory
https://www.vulncheck.com/advisories/nodemailer-before-10.0.6-denial-of-service-via-addressparser
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