Service interruption via quadratic address parsing
Published Sep 13, 2026 · Updated Sep 13, 2026
Algorithmic-complexity DoS in Nodemailer 9.1.0 through 10.0.4 allows remote attackers to stall Node.js services via crafted addresses. The addressparser join check calls slice(-1) on a growing accumulator before a cheap short-circuit, repeatedly flattening the string and producing quadratic work. Exposure requires attacker-controlled address input; mailparser supplies an unauthenticated remote path through inbound mail headers, and a 640 KB value blocks the event loop for about seven seconds.
Summary
What happened
Algorithmic-complexity DoS in Nodemailer 9.1.0 through 10.0.4 allows remote attackers to stall Node.js services via crafted addresses. The addressparser join check calls slice(-1) on a growing accumulator before a cheap short-circuit, repeatedly flattening the string and producing quadratic work. Exposure requires attacker-controlled address input; mailparser supplies an unauthenticated remote path through inbound mail headers, and a 640 KB value blocks the event loop for about seven seconds.
The record
- CVE
- CVE-2026-90776
- Published
- Sep 13, 2026
- Updated
- Sep 13, 2026
- Vendor
- Nodemailer
- Product
- Nodemailer
- Classifications
- CWE-407, CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 13, 2026CVE publishedPublication date reported by the CVE source.
- Sep 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=9.1.0 <10.0.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Nodemailer comment-joined address parser proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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