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.
Published: 2026-11-10
Score: 6.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 12 Nov 2026 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Postalsys
Postalsys postal-mime
Vendors & Products Postalsys
Postalsys postal-mime

Thu, 12 Nov 2026 01:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 10 Nov 2026 19:30:00 +0000

Type Values Removed Values Added
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.
Title postal-mime < 4.2.1 Algorithmic Complexity DoS via processLine
Weaknesses CWE-407
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


Subscriptions

Postalsys Postal-mime
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-13T20:29:09.130Z

Reserved: 2026-11-06T18:38:38.544Z

Link: CVE-2026-124016

cve-icon Vulnrichment

Updated: 2026-11-10T21:03:40.222Z

cve-icon NVD

Status : Deferred

Published: 2026-11-10T20:19:04.337

Modified: 2026-11-12T21:36:06.743

Link: CVE-2026-124016

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-13T12:30:04Z

Weaknesses
  • CWE-407

    Inefficient Algorithmic Complexity