CVE-2026-26961
Essential information
- Published
- 02/04/2026 17:16
- Modified
- 03/04/2026 16:10
- Author
- —
- Creator
- —
- CVSS
- 3.7 LOW (v3.1)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N—
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- HIGH
- Privileges required
- NONE
- User interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality impact
- NONE
- Integrity impact
- LOW
- Availability impact
- NONE
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Attack requirements
- —
- Privileges required
- —
- User interaction
- —
- Confidentiality (V)
- —
- Confidentiality (S)
- —
- Integrity (V)
- —
- Integrity (S)
- —
- Availability (V)
- —
- Availability (S)
- —
- Exploit maturity
- —
Description
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser extracts the boundary parameter from multipart/form-data using a greedy regular expression. When a Content-Type header contains multiple boundary parameters, Rack selects the last one rather than the first. In deployments where an upstream proxy, WAF, or intermediary interprets the first boundary parameter, this mismatch can allow an attacker to smuggle multipart content past upstream inspection and have Rack parse a different body structure than the intermediary validated. This issue has been patched in versions 2.2.23, 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 |
|---|---|
| rack / rack | cpe:2.3:a:rack:rack:<2.2.23:*:*:*:*:*:* |
| rack / rack | cpe:2.3:a:rack:rack:<3.1.21:*:*:*:*:*:* |
| rack / rack | cpe:2.3:a:rack:rack:<3.2.6:*:*:*:*:*:* |