CVE Explorer

CVE-2026-40934

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

Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:12f6a65d346fa5b8b558079a6c355065b8285ac589a73847539da094a41d5b2c

Known exploited

Not asserted

Disputed

Stale source

Conflicts

Affected products and versions

1 source assertion

{"product":"jupyter_server","vendor":"jupyter-server","versions":[{"status":"affected","version":"< 2.18.0"}]}

cve_program_cvelist_v5affected
urn:baitaphish:normalized-source-record:v2:5cc32080d738b1e0ee65959a9000283cb78955f760f9d4f02ae0f74f4b5b4fb5 · sha256:1da54849567ca1f7… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion

{"metric":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":7.6,"baseSeverity":"HIGH","privilegesRequired":"LOW","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","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","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH"},"metric_type":"cvssV4_0"}

cve_program_cvelist_v5cvss
urn:baitaphish:normalized-source-record:v2:5cc32080d738b1e0ee65959a9000283cb78955f760f9d4f02ae0f74f4b5b4fb5 · sha256:1da54849567ca1f7… · /containers/cna/metrics/0/cvssV4_0

CWE assertions

1 source assertion

{"cweId":"CWE-613","description":"CWE-613: Insufficient Session Expiration","lang":"en","type":"CWE"}

cve_program_cvelist_v5cwe
urn:baitaphish:normalized-source-record:v2:5cc32080d738b1e0ee65959a9000283cb78955f760f9d4f02ae0f74f4b5b4fb5 · sha256:1da54849567ca1f7… · /containers/cna/problemTypes/0/descriptions/0

Source references

1 source assertion

{"name":"https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f","tags":["x_refsource_CONFIRM"],"url":"https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:5cc32080d738b1e0ee65959a9000283cb78955f760f9d4f02ae0f74f4b5b4fb5 · sha256:1da54849567ca1f7… · /containers/cna/references/0

Attribution and limitations

CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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