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Fencer Intel
high 7.5

CVE-2026-110869 json

Nodemailer 3.0.0 before 10.0.13 ReDoS via SMTP AUTH Mechanism Detection Regexes

published 26d ago modified 13d ago also EUVD-2026-101752 , GHSA-4ffr-jq9g-5ffx

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

Nodemailer 3.0.0 before 10.0.13 has a regular expression denial of service in SMTPConnection._actionEHLO, whose four AUTH mechanism detection regexes contain overlapping whitespace sub-patterns that backtrack quadratically. A malicious or man-in-the-middle SMTP server can reply to EHLO with 250-AUTH, a long whitespace run and a non-matching token, blocking the Node.js event loop for tens of seconds to hours before authentication.

Patch / fix

  • npm nodemailer 10.0.13
  • nodemailer nodemailer 10.0.13
  • node-nodemailer Debian 14 10.0.13+~8.0.2-1

debian advisories DEBIAN-CVE-2026-110869

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-110869 updated cvss 7.5

nodemailer: nodemailer: Denial of Service via regular expression backtracking in SMTP authentication parsing

  • Red Hat Self-service automation portal 2 ansible-automation-platform/bootc-automation-portal-rhel9
    affected: workaround, no fix available
  • Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux 10 grafana 12.4.3-2.el10
    not affected: vulnerable code not present
  • Red Hat Hardened Images grafana13.1 13.1.7-0.1.hum1, grafana13.2 13.2.3-0.1.hum1, grafana12.4 12.4.12-0.4.hum1
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
25d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/nodemailer/nodemailer/security/advisories/GHSA-4ffr-jq9g-5ffx referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 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
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 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

Affected packages

ecosystem package affected fixed in
npm nodemailer
>=3.0.0, <10.0.13
10.0.13

Affected products

  • nodemailer nodemailer

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.