7.5High
CVE-2026-90776
Nodemailer versions 9.1.0 through 10.0.4 contain a quadratic time complexity vulnerability in the addressparser component when parsing email addresses with RFC 5322 comments. Attackers can craft malicious email headers with comment-separated atoms to consume excessive CPU and block the Node.js event loop for several seconds, causing denial of service.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 40% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- CVSS v4
- 8.7
- Weakness
- CWE-407
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-13
- Last modified
- 2026-09-16
- Sources
- NVD
References
- https://github.com/nodemailer/nodemailer
- https://github.com/nodemailer/nodemailer/blob/v10.0.4/src/addressparser/index.ts#L251
- https://github.com/nodemailer/nodemailer/commit/c07f17518d25aca8ab2ad66968dcbca538c24b89
- https://github.com/nodemailer/nodemailer/releases/tag/v10.0.5
- https://github.com/nodemailer/nodemailer/security/advisories/GHSA-prgh-xp8r-p3m5
- https://www.vulncheck.com/advisories/nodemailer-9.1.0-through-10.0.4-denial-of-service-via-quadratic-address-parsing
- https://github.com/nodemailer/nodemailer/security/advisories/GHSA-prgh-xp8r-p3m5