CVE-2026-34827
Essential information
- Published
- 02/04/2026 18:16
- Modified
- 03/04/2026 16:10
- Author
- —
- Creator
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- CVSS
- 7.5 HIGH (v3.1)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H—
CVSS metrics
- Access vector
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- Access complexity
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- Authentication
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- Confidentiality impact
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- Integrity impact
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- Availability impact
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- Exploitability
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- Remediation level
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- Report confidence
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- Temporal score
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- Attack vector
- NETWORK
- Attack complexity
- LOW
- Privileges required
- NONE
- User interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality impact
- NONE
- Integrity impact
- NONE
- Availability impact
- HIGH
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
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- Attack complexity
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- Attack requirements
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- Privileges required
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- User interaction
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- Confidentiality (V)
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- Confidentiality (S)
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- Integrity (V)
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- Integrity (S)
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- Availability (V)
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- Availability (S)
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- Exploit maturity
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Description
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.
NVD status
- Status
- Undergoing Analysis — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- [email protected]
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| ruby / rack | cpe:2.3:a:ruby:rack:3.0.0.beta1-3.1.20:*:*:*:*:*:*:* |
| ruby / rack | cpe:2.3:a:ruby:rack:3.2.0-3.2.5:*:*:*:*:*:*:* |