Service hang via backtracking-prone email parsing
Published Aug 31, 2026 · Updated Aug 31, 2026
Regular expression denial of service in Nodemailer 6.9.8 and earlier allows remote attackers to hang the Node.js event loop via crafted email content. The _processDataUrl path applies an unbounded repeated-group regex to attachment data URLs, while _convertDataImages scans HTML image tags with another backtracking-prone expression. Reachability requires an embedding application to process attacker-controlled embedded attachments or enable attachDataUrls; the resulting event-loop stall interrupts that Node.js service.
Summary
What happened
Regular expression denial of service in Nodemailer 6.9.8 and earlier allows remote attackers to hang the Node.js event loop via crafted email content. The _processDataUrl path applies an unbounded repeated-group regex to attachment data URLs, while _convertDataImages scans HTML image tags with another backtracking-prone expression. Reachability requires an embedding application to process attacker-controlled embedded attachments or enable attachDataUrls; the resulting event-loop stall interrupts that Node.js service.
The record
- CVE
- CVE-2024-58379
- Published
- Aug 31, 2026
- Updated
- Aug 31, 2026
- Vendor
- Nodemailer
- Product
- Nodemailer
- Classifications
- CWE-1333, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 31, 2026CVE publishedPublication date reported by the CVE source.
- Aug 31, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.9.9
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
- Embedded attachment data URL ReDoS PoCproof of concept · demonstrated
- attachDataUrls HTML image ReDoS PoCproof 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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo