CVE detail
CVE-2026-34827
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 16.1 · diversity 13.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
4 source links · newest first
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34827.jsonsecurity.access.redhat.com
No excerpt available.
Vendor Advisorysecurity.access.redhat.comApr 2, 2026, 6:16 PM - https://bugzilla.redhat.com/show_bug.cgi?id=2454501bugzilla.redhat.com
No excerpt available.
Exploitbugzilla.redhat.comApr 2, 2026, 6:16 PM - https://access.redhat.com/security/cve/CVE-2026-34827access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comApr 2, 2026, 6:16 PM No excerpt available.
Exploitgithub.comApr 2, 2026, 6:16 PM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
Related records
Similar CVEs
6 related CVEs with shared weakness or product evidence
- CVE-2026-49851CVSS 8.7 · High
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in…
- CVE-2026-45664CVSS 5.3 · Medium
ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-47 and 7.1.2-22, because of a missing check in the MNG code…
- CVE-2026-34829CVSS 7.5 · High
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENT_LENGTH is…
- CVE-2026-34826CVSS 5.3 · Medium
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.get_byte_ranges parses the HTTP Range header without limiting the number of i…
- CVE-2026-34230CVSS 5.3 · Medium
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time com…
- CVE-2025-59830CVSS 7.5 · High
Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::QueryParser enforces its params_limit only for parameters separated by &, while still splitting on both…