{"id":"CVE-2026-94206","state":"PUBLISHED","title":"Cloak PBKDF2 field ignores the configured iteration count and runs only :size rounds","description":"Use of Password Hash With Insufficient Computational Effort vulnerability in danielberkompas cloak_ecto and danielberkompas cloak allows an attacker who holds the hashed values and the configured secret to brute-force low-entropy plaintexts much faster than configured.\n\nThe dump/1 callback that Cloak.Ecto.PBKDF2 (Cloak.Fields.PBKDF2 in cloak before the Ecto code moved to cloak_ecto) injects into a field module calls :pbkdf2.pbkdf2/4 with config[:size] in the iteration-count position. The :iterations setting is validated but never used. With the cloak_ecto defaults (iterations: 600_000, size: 32) each hash runs 32 PBKDF2 rounds instead of 600,000, so offline guessing of values such as email addresses costs about 18,750 times less than configured.\n\nThis issue affects cloak_ecto: from 1.0.0-alpha.0 onward; cloak: from 0.7.0 before 1.0.0-alpha.0.","publishedAt":"2026-10-06T08:38:04.584Z","updatedAt":"2026-10-06T11:36:25.466Z","severity":{"score":6.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","source":"EEF"},"assigner":"EEF","products":["danielberkompas cloak_ecto","danielberkompas cloak"],"affected":[{"vendor":"danielberkompas","product":"cloak_ecto","packageName":"cloak_ecto","packageURL":"pkg:hex/cloak_ecto","defaultStatus":"unaffected","versions":[{"version":"1.0.0-alpha.0","status":"affected","lessThan":"*","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:danielberkompas:cloak_ecto:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Ecto.PBKDF2'"],"programFiles":["lib/cloak_ecto/types/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak_ecto"},{"vendor":"danielberkompas","product":"cloak_ecto","packageName":"danielberkompas/cloak_ecto","packageURL":"pkg:github/danielberkompas/cloak_ecto","defaultStatus":"unaffected","versions":[{"version":"a8fa1642b02f1c445a1ee8794c9095eb0921f8f3","status":"affected","lessThan":"*","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:danielberkompas:cloak_ecto:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Ecto.PBKDF2'"],"programFiles":["lib/cloak_ecto/types/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak_ecto"},{"vendor":"danielberkompas","product":"cloak","packageName":"cloak","packageURL":"pkg:hex/cloak","defaultStatus":"unaffected","versions":[{"version":"0.7.0","status":"affected","lessThan":"1.0.0-alpha.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:danielberkompas:cloak:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Fields.PBKDF2'"],"programFiles":["lib/cloak/fields/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak"},{"vendor":"danielberkompas","product":"cloak","packageName":"danielberkompas/cloak","packageURL":"pkg:github/danielberkompas/cloak","defaultStatus":"unaffected","versions":[{"version":"8699e6417a162c39d9f0ef63511bd23d3f38d1d2","status":"affected","lessThan":"681c9702b7cd9afe0e5a840751ab009f550c69a9","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:danielberkompas:cloak:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Fields.PBKDF2'"],"programFiles":["lib/cloak/fields/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak"}],"references":["https://cna.erlef.org/cves/CVE-2026-94206.html","https://osv.dev/vulnerability/EEF-CVE-2026-94206","https://github.com/danielberkompas/cloak_ecto/commit/a8fa1642b02f1c445a1ee8794c9095eb0921f8f3","https://github.com/danielberkompas/cloak/commit/8699e6417a162c39d9f0ef63511bd23d3f38d1d2","https://github.com/danielberkompas/cloak/commit/681c9702b7cd9afe0e5a840751ab009f550c69a9"],"weaknesses":["CWE-916"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/94xxx/CVE-2026-94206.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-94206","state":"PUBLISHED","datePublished":"2026-10-06T08:38:04.584Z","dateUpdated":"2026-10-06T11:36:25.466Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-09-24T09:30:02.102Z"},"containers":{"cna":{"title":"Cloak PBKDF2 field ignores the configured iteration count and runs only :size rounds","descriptions":[{"lang":"en","value":"Use of Password Hash With Insufficient Computational Effort vulnerability in danielberkompas cloak_ecto and danielberkompas cloak allows an attacker who holds the hashed values and the configured secret to brute-force low-entropy plaintexts much faster than configured.\n\nThe dump/1 callback that Cloak.Ecto.PBKDF2 (Cloak.Fields.PBKDF2 in cloak before the Ecto code moved to cloak_ecto) injects into a field module calls :pbkdf2.pbkdf2/4 with config[:size] in the iteration-count position. The :iterations setting is validated but never used. With the cloak_ecto defaults (iterations: 600_000, size: 32) each hash runs 32 PBKDF2 rounds instead of 600,000, so offline guessing of values such as email addresses costs about 18,750 times less than configured.\n\nThis issue affects cloak_ecto: from 1.0.0-alpha.0 onward; cloak: from 0.7.0 before 1.0.0-alpha.0."}],"affected":[{"vendor":"danielberkompas","product":"cloak_ecto","packageName":"cloak_ecto","packageURL":"pkg:hex/cloak_ecto","defaultStatus":"unaffected","versions":[{"version":"1.0.0-alpha.0","status":"affected","lessThan":"*","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:danielberkompas:cloak_ecto:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Ecto.PBKDF2'"],"programFiles":["lib/cloak_ecto/types/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak_ecto"},{"vendor":"danielberkompas","product":"cloak_ecto","packageName":"danielberkompas/cloak_ecto","packageURL":"pkg:github/danielberkompas/cloak_ecto","defaultStatus":"unaffected","versions":[{"version":"a8fa1642b02f1c445a1ee8794c9095eb0921f8f3","status":"affected","lessThan":"*","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:danielberkompas:cloak_ecto:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Ecto.PBKDF2'"],"programFiles":["lib/cloak_ecto/types/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak_ecto"},{"vendor":"danielberkompas","product":"cloak","packageName":"cloak","packageURL":"pkg:hex/cloak","defaultStatus":"unaffected","versions":[{"version":"0.7.0","status":"affected","lessThan":"1.0.0-alpha.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:danielberkompas:cloak:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Fields.PBKDF2'"],"programFiles":["lib/cloak/fields/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak"},{"vendor":"danielberkompas","product":"cloak","packageName":"danielberkompas/cloak","packageURL":"pkg:github/danielberkompas/cloak","defaultStatus":"unaffected","versions":[{"version":"8699e6417a162c39d9f0ef63511bd23d3f38d1d2","status":"affected","lessThan":"681c9702b7cd9afe0e5a840751ab009f550c69a9","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:danielberkompas:cloak:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Cloak.Fields.PBKDF2'"],"programFiles":["lib/cloak/fields/pbkdf2.ex"],"repo":"https://github.com/danielberkompas/cloak"}],"references":[{"url":"https://cna.erlef.org/cves/CVE-2026-94206.html","name":"EEF CNA record for CVE-2026-94206","tags":["related","third-party-advisory"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-94206","name":"OSV record EEF-CVE-2026-94206","tags":["related"]},{"url":"https://github.com/danielberkompas/cloak_ecto/commit/a8fa1642b02f1c445a1ee8794c9095eb0921f8f3","name":"Introducing commit a8fa164 in danielberkompas/cloak_ecto","tags":["related"]},{"url":"https://github.com/danielberkompas/cloak/commit/8699e6417a162c39d9f0ef63511bd23d3f38d1d2","name":"Introducing commit 8699e64 in danielberkompas/cloak","tags":["related"]},{"url":"https://github.com/danielberkompas/cloak/commit/681c9702b7cd9afe0e5a840751ab009f550c69a9","name":"Fix commit 681c970 in danielberkompas/cloak","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-916","description":"CWE-916 Use of Password Hash With Insufficient Computational Effort","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-10-06T08:38:04.584Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:danielberkompas:cloak_ecto:*:*:*:*:*:*:*:*","versionStartIncluding":"1.0.0-alpha.0","vulnerable":true},{"criteria":"cpe:2.3:a:danielberkompas:cloak:*:*:*:*:*:*:*:*","versionEndExcluding":"1.0.0-alpha.0","versionStartIncluding":"0.7.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"}],"dateAssigned":"2026-10-06T08:35:00.000Z","impacts":[{"capecId":"CAPEC-55","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"

An attacker who obtains a database dump and the PBKDF2 secret can recover hashed values with low entropy, such as email addresses, by offline guessing at a cost far below what the configuration promises.

"},{"base64":false,"type":"text/markdown","value":"An attacker who obtains a database dump and the PBKDF2 secret can recover hashed values with low entropy, such as email addresses, by offline guessing at a cost far below what the configuration promises."}],"value":"An attacker who obtains a database dump and the PBKDF2 secret can recover hashed values with low entropy, such as email addresses, by offline guessing at a cost far below what the configuration promises."}]}],"source":{"discovery":"EXTERNAL"},"workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"

Override dump/1 in the field module that uses Cloak.Ecto.PBKDF2, so that it calls :pbkdf2.pbkdf2/5 with the configured :iterations and :size. Then recompute all stored hashes, because the existing values no longer match.

"},{"base64":false,"type":"text/markdown","value":"Override `dump/1` in the field module that uses `Cloak.Ecto.PBKDF2`, so that it calls `:pbkdf2.pbkdf2/5` with the configured `:iterations` and `:size`. Then recompute all stored hashes, because the existing values no longer match."}],"value":"Override dump/1 in the field module that uses Cloak.Ecto.PBKDF2, so that it calls :pbkdf2.pbkdf2/5 with the configured :iterations and :size. Then recompute all stored hashes, because the existing values no longer match."}],"x_proofOfConcept":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"
    \n
  1. Define a field module with use Cloak.Ecto.PBKDF2 and configure only a :secret, so that the defaults iterations: 600_000 and size: 32 apply.
    2. \n
  2. Call dump/1 on a value.
    3. \n
  3. Compare the result with :pbkdf2.pbkdf2({:hmac, :sha256}, value, secret, 32) and with the same call at 600,000 rounds. It matches the 32-round hash, not the 600,000-round hash, and returns in microseconds instead of about one second.
    4. \n
"},{"base64":false,"type":"text/markdown","value":"1. Define a field module with `use Cloak.Ecto.PBKDF2` and configure only a `:secret`, so that the defaults `iterations: 600_000` and `size: 32` apply.\n2. Call `dump/1` on a value.\n3. Compare the result with `:pbkdf2.pbkdf2({:hmac, :sha256}, value, secret, 32)` and with the same call at 600,000 rounds. It matches the 32-round hash, not the 600,000-round hash, and returns in microseconds instead of about one second."}],"value":"* Define a field module with use Cloak.Ecto.PBKDF2 and configure only a :secret, so that the defaults iterations: 600_000 and size: 32 apply.\n* Call dump/1 on a value.\n* Compare the result with :pbkdf2.pbkdf2({:hmac, :sha256}, value, secret, 32) and with the same call at 600,000 rounds. It matches the 32-round hash, not the 600,000-round hash, and returns in microseconds instead of about one second."}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-06T11:34:00.942993Z","id":"CVE-2026-94206","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-06T11:36:25.466Z"}}]}}}