All errata/sisyphus/ALT-PU-2026-7460-3
ALT-PU-2026-7460-3

Package update python3-module-jupyter_server in branch sisyphus

Version2.18.0-alt1
Task#417181
Published2026-06-05
Max severityHIGH
Severity:

Closed issues (9)

CVE-2025-61669
MEDIUM6.3

Jupyter Server is the backend for Jupyter web applications. In jupyter_server versions through 2.17.0, the next query parameter in the login flow is insufficiently validated in `LoginFormHandler._redirect_safe()`, which allows redirects to arbitrary external domains via values such as `///example.com`. An attacker can use a crafted login URL to redirect users to a malicious site and facilitate phishing attacks. This issue is fixed in version 2.18.0.

Published: 2026-05-05Modified: 2026-06-17
CVSS 3.xMEDIUM 6.1
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS 4.0MEDIUM 6.3
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-35397
HIGH7.6

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, a path traversal vulnerability in the REST API allows an authenticated user to escape the configured root_dir and access sibling directories whose names begin with the same prefix as the root_dir. For example, with a root_dir named "test", the API permits access to a sibling directory named "testtest" through a crafted request to the /api/contents endpoint using encoded path components. An attacker can read, write, and delete files in affected sibling directories. Multi-tenant deployments using predictable naming schemes are particularly at risk, as a user with a directory named "user1" could access directories for user10 through user19 and beyond. A user who can choose a single-character folder name could gain access to a significant number of sibling directories. Version 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory.

Published: 2026-05-05Modified: 2026-06-17
CVSS 3.xHIGH 8.8
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-40110
HIGH7.6

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.

Published: 2026-05-05Modified: 2026-06-17
CVSS 3.xHIGH 7.3
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-40934
HIGH7.6

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the secret used to sign authentication cookies is persisted to a static file at ~/.local/share/jupyter/runtime/jupyter_cookie_secret and is never rotated when a user changes their password. After a password reset and server restart, any previously issued authentication cookie remains cryptographically valid because the signing key has not changed. An attacker who has captured a session cookie through any means retains full authenticated access to the server regardless of subsequent password changes. This affects deployments using password-based authentication, particularly shared or public-facing servers where credential rotation is expected to revoke existing sessions. This issue has been fixed in version 2.18.0.

Published: 2026-05-05Modified: 2026-06-17
CVSS 3.xMEDIUM 6.8
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-5422
HIGH8.1

A path traversal vulnerability exists in jupyter-server version 2.17.0 due to an incorrect root directory boundary check in the _get_os_path() function within jupyter_server/services/contents/fileio.py. The check uses startswith(root) without appending a trailing path separator, allowing sibling directories with names starting with the same prefix as root_dir to bypass the check. Additionally, the to_os_path() function in utils.py does not strip ".." from path parts, enabling traversal sequences to bypass the vulnerable check. This vulnerability can lead to unauthorized read/write access to files in sibling directories, potentially exposing sensitive data in shared hosting environments.

Published: 2026-06-02Modified: 2026-06-17
CVSS 3.xHIGH 8.1
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
GHSA-24qx-w28j-9m6p
HIGH7.6

Jupyter Server has a CORS Origin Validation Bypass via `re.match()` in `allow_origin_pat` (from huntr)

Published: 2026-05-05Modified: 2026-05-08
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L
References
GHSA-5789-5fc7-67v3
HIGH7.6

Jupyter Server: Path Traversal via incorrect startswith() root directory check allows access to sibling directories

Published: 2026-05-05Modified: 2026-06-06
CVSS 3.x
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
References
GHSA-5mrq-x3x5-8v8f
HIGH7.6

Jupyter Server's Authentication Cookies Remain Valid After Password Reset and Server Restart

Published: 2026-05-05Modified: 2026-06-06
CVSS 3.x
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS 4.0HIGH 7.6
CVSS:4.0/CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References
GHSA-qh7q-6qm3-653w
MEDIUM6.0

Jupyter Server has an open redirection vulnerability in `next` query parameter

Published: 2026-05-05Modified: 2026-06-05
CVSS 4.0MEDIUM 6.0
CVSS:4.0/CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
References