{"id":"CVE-2026-40934","state":"PUBLISHED","title":"jupyter-server authentication cookies remain valid after password reset due to static cookie secret","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.","publishedAt":"2026-05-05T21:31:42.897Z","updatedAt":"2026-05-07T12:48:21.223Z","severity":{"score":7.6,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["jupyter-server jupyter_server"],"affected":[{"vendor":"jupyter-server","product":"jupyter_server","versions":[{"version":"< 2.18.0","status":"affected"}]}],"references":["https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f"],"weaknesses":["CWE-613"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40934.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40934","state":"PUBLISHED","datePublished":"2026-05-05T21:31:42.897Z","dateUpdated":"2026-05-07T12:48:21.223Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-15T20:40:15.518Z"},"containers":{"cna":{"title":"jupyter-server authentication cookies remain valid after password reset due to static cookie secret","descriptions":[{"lang":"en","value":"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":[{"vendor":"jupyter-server","product":"jupyter_server","versions":[{"version":"< 2.18.0","status":"affected"}]}],"references":[{"url":"https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f","name":"https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.6,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-613","lang":"en","description":"CWE-613: Insufficient Session Expiration","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-05T21:31:42.897Z"},"source":{"advisory":"GHSA-5mrq-x3x5-8v8f","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-07T03:55:46.015938Z","id":"CVE-2026-40934","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-07T12:48:21.223Z"}}]}}}