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CVE-2026-39324

Rack::Session is a session management implementation for Rack. From 2.0.0 to before 2.1.2, Rack::Session::Cookie incorrectly handles decryption failures when configured with secrets:. If cookie decryption fails, the implementation falls back to a default decoder instead of rejecting the cookie. This allows an unauthenticated attacker to supply a crafted session cookie that is accepted as valid session data without knowledge of any configured secret. Because this mechanism is used to load session
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:f5b239898f0b857994a6862d3f654ba19c27e58070c11d89ab4c6dd123e2b15c
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
1

Preserved source conflicts

No provider value was silently selected as the winner.

cwe · 4 assertions

{"cweId":"CWE-502","description":"CWE-502: Deserialization of Untrusted Data","lang":"en","type":"CWE"}

  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/2/descriptions/0

{"cweId":"CWE-565","description":"CWE-565: Reliance on Cookies without Validation and Integrity Checking","lang":"en","type":"CWE"}

  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/3/descriptions/0

{"cweId":"CWE-345","description":"CWE-345: Insufficient Verification of Data Authenticity","lang":"en","type":"CWE"}

  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/1/descriptions/0

{"cweId":"CWE-287","description":"CWE-287: Improper Authentication","lang":"en","type":"CWE"}

  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/0/descriptions/0

Affected products and versions

1 source assertion
{"product":"rack-session","vendor":"rack","versions":[{"status":"affected","version":">= 2.0.0, < 2.1.2"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion
{"metric":{"attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":9.3,"baseSeverity":"CRITICAL","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH"},"metric_type":"cvssV4_0"}
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/metrics/0/cvssV4_0

CWE assertions

4 source assertions
{"cweId":"CWE-502","description":"CWE-502: Deserialization of Untrusted Data","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/2/descriptions/0
{"cweId":"CWE-565","description":"CWE-565: Reliance on Cookies without Validation and Integrity Checking","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/3/descriptions/0
{"cweId":"CWE-345","description":"CWE-345: Insufficient Verification of Data Authenticity","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/1/descriptions/0
{"cweId":"CWE-287","description":"CWE-287: Improper Authentication","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /containers/cna/problemTypes/0/descriptions/0

Source references

1 source assertion
{"name":"https://github.com/rack/rack-session/security/advisories/GHSA-33qg-7wpp-89cq","tags":["x_refsource_CONFIRM"],"url":"https://github.com/rack/rack-session/security/advisories/GHSA-33qg-7wpp-89cq"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:2d596e28ddc69a5ce76656804090c3ed0eb3953c60c01e71ef032287552726b8 · sha256:4abbd95792bb360b… · /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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