CVE-2026-124016
Received
Received - Intake
Postal-Mime Algorithm Complexity DoS via Nested Multipart Emails
Vulnerability report for CVE-2026-124016, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-10
Last updated on: 2026-11-10
Assigner: VulnCheck
Description
Description
postal-mime before 4.2.1 contains an algorithmic complexity denial of service vulnerability that allows unauthenticated remote attackers to cause excessive CPU consumption in the PostalMime.processLine() function by crafting deeply nested multipart email messages with boundary lines sharing long prefixes with open boundaries. Attackers can deliver a malicious email with nesting up to the default maxNestingDepth of 256, causing per-line parsing cost to scale as O(depth x shared prefix length) and blocking the Node.js event loop for seconds per message.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| postalsys | postal-mime | From 0 (inc) to 4.2.1 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-407 | An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached. |
