CVE-2026-44727

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Source
https://cve.org/CVERecord?id=CVE-2026-44727
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44727.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-44727
Aliases
Downstream
Related
Published
2026-06-22T19:56:56.776Z
Modified
2026-07-09T03:51:39.630540797Z
Severity
  • 9.3 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H CVSS Calculator
Summary
Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP
Details

Jupyter Server is the backend for Jupyter web applications. Prior to 2.20, the nbconvert HTTP handlers in jupyterserver render user-authored notebook HTML under the Jupyter origin without a sandbox directive in their Content-Security-Policy. Combined with nbconvert.HTMLExporter's default non-sanitizing behavior, a notebook carrying an HTML payload in a displaydata output triggers stored XSS with cookie access, full /api/* authority, and kernel RCE. This vulnerability is fixed in 2.20.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44727.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-1021",
        "CWE-79"
    ]
}
References

Affected packages

Git / github.com/jupyter-server/jupyter_server

Affected ranges

Type
GIT
Repo
https://github.com/jupyter-server/jupyter_server
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
05a78ad879e69ef87e91b2714a8ebeb5ff9628a7
Fixed
6cbee8d65e71abac851c4492fea987ad080580bd
Database specific 
{
    "cpe": "cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.20.0"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

0.*
0.0.1
0.0.2
0.0.3
0.0.4
0.0.5
0.1.0
0.1.1
0.2.0
0.3.0
1.*
1.0.0
1.0.0rc1
1.0.0rc10
1.0.0rc11
1.0.0rc12
1.0.0rc13
1.0.0rc14
1.0.0rc15
1.0.0rc16
1.0.0rc2
1.0.0rc3
1.0.0rc4
1.0.0rc5
1.0.0rc6
1.0.0rc7
1.0.0rc8
1.0.0rc9
1.0.1
1.0.2
1.0.3
1.0.4
1.0.5
1.1.0
1.1.1
1.1.2
1.1.3
1.1.4
1.2.0
1.2.1
1.2.2
1.2.3
1.3.0
1.4.0
1.4.1
1.5.0
1.5.1
1.6.0
1.6.1
v1.*
v1.10.0
v1.10.1
v1.10.2
v1.11.0
v1.11.1
v1.11.2
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
v1.6.2
v1.6.3
v1.6.4
v1.7.0
v1.7.0a0
v1.7.0a1
v1.7.0a2
v1.8.0
v1.9.0
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
v2.18.0
v2.18.1
v2.18.2
v2.19.0
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-2026-44727.json"