CVE-2025-25186Public exploitNetwork attack vector

Client denial of service via unbounded uid-set expansion

Published Feb 10, 2025 · Updated Feb 12, 2025

Denial of service in affected Ruby net-imap releases allows remote attackers to exhaust client memory via malicious IMAP responses. Net::IMAP::ResponseParser expands APPENDUID and COPYUID uid-set ranges with Range#to_a without limiting the resulting integer arrays. The client must connect to a malicious or compromised IMAP server; its receiver thread parses the response even when the application ignores it, exhausting memory and interrupting the client process.

CVSS severity6.0
Medium
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected Ruby net-imap releases allows remote attackers to exhaust client memory via malicious IMAP responses. Net::IMAP::ResponseParser expands APPENDUID and COPYUID uid-set ranges with Range#to_a without limiting the resulting integer arrays. The client must connect to a malicious or compromised IMAP server; its receiver thread parses the response even when the application ignores it, exhausting memory and interrupting the client process.

The record

CVE
CVE-2025-25186
Published
Feb 10, 2025
Updated
Feb 12, 2025
Vendor
Ruby
Product
net-imap
Classifications
CWE-409, CWE-789, CWE-1287, CWE-400, CWE-770, CWE-405, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record 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.

  1. Affected versionversion=>= 0.3.2, < 0.3.8
  2. Affected versionversion=>= 0.4.0, < 0.4.19
  3. Affected versionversion=>= 0.5.0, < 0.5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ruby · net-imapversion=>= 0.3.2, < 0.3.8; version=>= 0.4.0, < 0.4.19; version=>= 0.5.0, < 0.5.6

Published CVSS scores

6.0GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
CWE-789Memory Allocation with Excessive Size Value
CWE-1287Improper Validation of Specified Type of Input
CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
CWE-405Asymmetric Resource Consumption (Amplification)
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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