7.5

CVE-2026-34827

Rack: Algorithmic-Complexity DoS in Rack::Multipart::Parser

Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Multipart::Parser#handle_mime_head parses quoted multipart parameters such as Content-Disposition: form-data; name="..." using repeated String#index searches combined with String#slice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing. An unauthenticated attacker can send a crafted multipart/form-data request containing many parts with long backslash-escaped parameter values to trigger excessive CPU usage during multipart parsing. This results in a denial of service condition in Rack applications that accept multipart form data. This issue has been patched in versions 3.1.21 and 3.2.6.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Rack ≫ Rack SwPlatformruby Version >= 3.0.0 < 3.1.21
Rack ≫ Rack SwPlatformruby Version >= 3.2.0 < 3.2.6
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.48% 0.375
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
0b0ca135-0b70-47e7-9f44-1890c2a1c46c 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

CWE-407 Inefficient Algorithmic Complexity

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.

CWE-770 Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

https://github.com/rack/rack/security/advisories/GHSA-v6x5-cg8r-vv6x
Vendor Advisory
Mitigation
https://access.redhat.com/security/cve/CVE-2026-34827
https://bugzilla.redhat.com/show_bug.cgi?id=2454501
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34827.json