CVE-2025-61772Network attack vector

Application crash via unbounded multipart header buffering

Published Oct 7, 2025 · Updated Oct 7, 2025

Uncontrolled resource consumption in Rack before 2.2.19, 3.1.17, and 3.2.2 allows remote attackers to crash applications via multipart requests. Rack::Multipart::Parser waits for a terminating CRLFCRLF sequence while appending incoming header bytes to an uncapped buffer. The affected application must parse multipart input; incomplete part headers can exhaust process memory, causing severe slowdown or termination.

CVSS severity7.5
High
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Rack before 2.2.19, 3.1.17, and 3.2.2 allows remote attackers to crash applications via multipart requests. Rack::Multipart::Parser waits for a terminating CRLFCRLF sequence while appending incoming header bytes to an uncapped buffer. The affected application must parse multipart input; incomplete part headers can exhaust process memory, causing severe slowdown or termination.

The record

CVE
CVE-2025-61772
Published
Oct 7, 2025
Updated
Oct 7, 2025
Vendor
Rack
Product
Rack
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 7, 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=< 2.2.19
  2. Affected versionversion=>= 3.1, < 3.1.17
  3. Affected versionversion=>= 3.2, < 3.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rack · Rackversion=< 2.2.19; version=>= 3.1, < 3.1.17; version=>= 3.2, < 3.2.2

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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