CVEvulnerability
CVE-2026-40934
7.6 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-05
- Last modified
- 2026-07-25
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 7.6 HIGH — 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
- CVSS 3.1 ([email protected])
- 6.8 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-613
Description
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.
Affected configurations
• jupyter jupyter server (< 2.18.0)
Related
Weakness · not in database (1)
References
- https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f Exploit, Mitigation, Vendor Advisory