CVE-2026-6657
Essential information
- Published
- 03/06/2026 18:16
- Modified
- —
- Author
- The MITRE Corporation
- Creator
- The MITRE Corporation
- CVSS
- 8.8 HIGH (v3.1)
- CISA KEV
- No
- CWE
- CWE-346
- EPSS (First)
- P3.2% EPSS percentile: rank of this vulnerability versus all others. Higher percentile = more likely to be exploited. Learn more (score 0.00134)
- CVSS vector
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CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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
- REQUIRED
- Scope
- UNCHANGED
- Confidentiality impact
- HIGH
- Integrity impact
- HIGH
- Availability impact
- HIGH
- Exploit code maturity
- —
- Remediation level
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- Report confidence
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- Temporal score
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- 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
A vulnerability in jupyter-server versions 1.12.0 through 2.17.0 allows an attacker to bypass CORS origin validation when the `allow_origin_pat` configuration is used. The issue arises from the use of `re.match()` for validating the `Origin` header, which only anchors at the start of the string. This allows attacker-controlled domains such as `trusted.example.com.evil.com` to pass validation against patterns intended to match `trusted.example.com`. The vulnerability affects multiple locations in the codebase, including CORS headers, WebSocket connections, referer validation, and login redirects, potentially enabling phishing attacks, arbitrary code execution, and unauthorized access to sensitive API responses.
NVD status
- NVD
- View on NVD