CVE-2026-6657

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-6657
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6657.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-6657
Aliases
Downstream
Published
2026-06-03T15:06:56.598Z
Modified
2026-07-23T15:11:47.231076569Z
Severity
  • 6.1 (Medium) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
Summary
CORS Origin Validation Bypass in jupyter-server
Details

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.

Database specific 
{
    "cwe_ids": [
        "CWE-346"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6657.json",
    "cna_assigner": "@huntr_ai",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "1.12.0"
                },
                {
                    "fixed": "2.17.0"
                }
            ],
            "source": "DESCRIPTION"
        }
    ]
}
References

Affected packages

Git / github.com/jupyter-server/jupyter_server

Affected ranges

Type
GIT
Repo
https://github.com/jupyter-server/jupyter_server
Events
Introduced
fe4170278b0699e43f76a4647047dd5ed29fc23f
Last affected
3b03c644b56cf100f4535f70e2e8f4a45a57a5b8
Database specific 
{
    "cpe": "cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "1.12.0"
        },
        {
            "last_affected": "2.17.0"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

v1.*
v1.12.0
v1.12.1
v1.13.0
v1.13.1
v1.13.2
v1.13.3
v1.13.4
v1.13.5
v1.15.0
v1.15.1
v1.15.2
v1.15.3
v1.15.4
v1.15.5
v1.15.6
v1.16.0
v2.*
v2.0.0
v2.0.0a0
v2.0.0a1
v2.0.0a2
v2.0.0b0
v2.0.0b1
v2.0.0rc0
v2.0.0rc1
v2.0.0rc2
v2.0.0rc3
v2.0.0rc4
v2.0.0rc5
v2.0.0rc6
v2.0.0rc7
v2.0.0rc8
v2.0.1
v2.0.2
v2.0.3
v2.0.4
v2.0.5
v2.0.6
v2.0.7
v2.1.0
v2.10.0
v2.10.1
v2.11.0
v2.11.1
v2.11.2
v2.12.0
v2.12.1
v2.12.2
v2.12.3
v2.12.4
v2.12.5
v2.13.0
v2.14.0
v2.14.1
v2.14.2
v2.15.0
v2.16.0
v2.17.0
v2.2.0
v2.2.1
v2.3.0
v2.4.0
v2.5.0
v2.6.0
v2.7.0
v2.7.1
v2.7.2
v2.7.3
v2.8.0
v2.9.0
v2.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6657.json"