Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Nodemailer versions 9.1.0 up to 10.0.5 (excluding 10.0.5) are affected by a quadratic-time parsing flaw in the addressparser module, which mailparser also uses on inbound email headers. A remote attacker can send one crafted email with a very long comment-joined address, requiring no authentication, to block the Node.js event loop for several seconds and stall a service that parses mail. The fix is to upgrade nodemailer to version 10.0.5.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.7 | High | 4.0 | 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 (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0068, the 53rd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:34 UTC First seen by agentprime
- 31 Oct 2026, 13:34 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-prgh-xp8r-p3m5
- OSV: GHSA-prgh-xp8r-p3m5
- github.com/nodemailer/nodemailer/security/advisories/GHSA-prgh-xp8r-p3m5
- nvd.nist.gov/vuln/detail/CVE-2026-90776
- github.com/nodemailer/nodemailer/commit/c07f17518d25aca8ab2ad66968dcbca538c24b89
- github.com/nodemailer/nodemailer
- github.com/nodemailer/nodemailer/releases/tag/v10.0.5
- www.vulncheck.com/advisories/nodemailer-9.1.0-through-10.0.4-denial-of-service-via-quadratic-address-parsing