{"id":"CVE-2026-65627","state":"PUBLISHED","title":"Decompression bomb via unbounded zlib:inflate in jose_jwe_zip:uncompress/2","description":"Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in potatosalad jose (erlang-jose) allows a remote attacker to exhaust a node's memory with a small crafted JWE token.\n\nThe jose_jwe_zip:uncompress/2 function in src/jwe/jose_jwe_zip.erl decompresses the DEFLATE-compressed plaintext of a JWE that carries the optional zip: DEF header by calling zlib:inflate/2 on the entire attacker-controlled stream, with no bound on the output size or the inflation ratio. Raw DEFLATE reaches ratios around 1000:1 on highly repetitive input, so a few-kilobyte token inflates to hundreds of megabytes or gigabytes in a single call.\n\nDecompression runs automatically during decryption through jose_jwe:block_decrypt/2 (JOSE.JWE.block_decrypt/2 in Elixir), before the recipient can inspect or reject the payload. With the common asymmetric key-management algorithms (RSA-OAEP, ECDH-ES) an attacker needs only the recipient's public key to craft such a token, so no authentication or secret material is required. A single small token can exhaust the node's memory and crash the BEAM, denying service to all users.\n\nThis issue affects jose: from 1.0.0 before 1.11.13.","publishedAt":"2026-10-26T19:53:16.336Z","updatedAt":"2026-10-26T19:53:16.336Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"EEF"},"assigner":"EEF","products":["potatosalad jose"],"affected":[{"vendor":"potatosalad","product":"jose","packageName":"jose","packageURL":"pkg:hex/jose","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"1.11.13","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"],"modules":["jose_jwe_zip","jose_jwe","'Elixir.JOSE.JWE'"],"programFiles":["src/jwe/jose_jwe_zip.erl","src/jwe/jose_jwe.erl","lib/jose/jwe.ex"],"programRoutines":[{"name":"jose_jwe_zip:uncompress/2"},{"name":"jose_jwe:block_decrypt/2"},{"name":"'Elixir.JOSE.JWE':block_decrypt/2"}],"repo":"https://github.com/potatosalad/erlang-jose"},{"vendor":"potatosalad","product":"jose","packageName":"potatosalad/erlang-jose","packageURL":"pkg:github/potatosalad/erlang-jose","defaultStatus":"unaffected","versions":[{"version":"a7746ecd4950f85a393136e449a91dac62b5c429","status":"affected","lessThan":"857eb8e7f2d33e2c9ca2189e77226561cacaf2ad","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"],"modules":["jose_jwe_zip","jose_jwe","'Elixir.JOSE.JWE'"],"programFiles":["src/jwe/jose_jwe_zip.erl","src/jwe/jose_jwe.erl","lib/jose/jwe.ex"],"programRoutines":[{"name":"jose_jwe_zip:uncompress/2"},{"name":"jose_jwe:block_decrypt/2"},{"name":"'Elixir.JOSE.JWE':block_decrypt/2"}],"repo":"https://github.com/potatosalad/erlang-jose"}],"references":["https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-wfpv-qxp8-x5gm","https://cna.erlef.org/cves/CVE-2026-65627.html","https://osv.dev/vulnerability/EEF-CVE-2026-65627","https://github.com/potatosalad/erlang-jose/commit/a7746ecd4950f85a393136e449a91dac62b5c429","https://github.com/potatosalad/erlang-jose/commit/857eb8e7f2d33e2c9ca2189e77226561cacaf2ad"],"weaknesses":["CWE-409"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/65xxx/CVE-2026-65627.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-65627","state":"PUBLISHED","datePublished":"2026-10-26T19:53:16.336Z","dateUpdated":"2026-10-26T19:53:16.336Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-07-22T13:58:26.233Z"},"containers":{"cna":{"title":"Decompression bomb via unbounded zlib:inflate in jose_jwe_zip:uncompress/2","descriptions":[{"lang":"en","value":"Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in potatosalad jose (erlang-jose) allows a remote attacker to exhaust a node's memory with a small crafted JWE token.\n\nThe jose_jwe_zip:uncompress/2 function in src/jwe/jose_jwe_zip.erl decompresses the DEFLATE-compressed plaintext of a JWE that carries the optional zip: DEF header by calling zlib:inflate/2 on the entire attacker-controlled stream, with no bound on the output size or the inflation ratio. Raw DEFLATE reaches ratios around 1000:1 on highly repetitive input, so a few-kilobyte token inflates to hundreds of megabytes or gigabytes in a single call.\n\nDecompression runs automatically during decryption through jose_jwe:block_decrypt/2 (JOSE.JWE.block_decrypt/2 in Elixir), before the recipient can inspect or reject the payload. With the common asymmetric key-management algorithms (RSA-OAEP, ECDH-ES) an attacker needs only the recipient's public key to craft such a token, so no authentication or secret material is required. A single small token can exhaust the node's memory and crash the BEAM, denying service to all users.\n\nThis issue affects jose: from 1.0.0 before 1.11.13."}],"affected":[{"vendor":"potatosalad","product":"jose","packageName":"jose","packageURL":"pkg:hex/jose","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"1.11.13","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"],"modules":["jose_jwe_zip","jose_jwe","'Elixir.JOSE.JWE'"],"programFiles":["src/jwe/jose_jwe_zip.erl","src/jwe/jose_jwe.erl","lib/jose/jwe.ex"],"programRoutines":[{"name":"jose_jwe_zip:uncompress/2"},{"name":"jose_jwe:block_decrypt/2"},{"name":"'Elixir.JOSE.JWE':block_decrypt/2"}],"repo":"https://github.com/potatosalad/erlang-jose"},{"vendor":"potatosalad","product":"jose","packageName":"potatosalad/erlang-jose","packageURL":"pkg:github/potatosalad/erlang-jose","defaultStatus":"unaffected","versions":[{"version":"a7746ecd4950f85a393136e449a91dac62b5c429","status":"affected","lessThan":"857eb8e7f2d33e2c9ca2189e77226561cacaf2ad","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"],"modules":["jose_jwe_zip","jose_jwe","'Elixir.JOSE.JWE'"],"programFiles":["src/jwe/jose_jwe_zip.erl","src/jwe/jose_jwe.erl","lib/jose/jwe.ex"],"programRoutines":[{"name":"jose_jwe_zip:uncompress/2"},{"name":"jose_jwe:block_decrypt/2"},{"name":"'Elixir.JOSE.JWE':block_decrypt/2"}],"repo":"https://github.com/potatosalad/erlang-jose"}],"references":[{"url":"https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-wfpv-qxp8-x5gm","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-65627.html","name":"EEF CNA record for CVE-2026-65627","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-65627","name":"OSV record EEF-CVE-2026-65627","tags":["related"]},{"url":"https://github.com/potatosalad/erlang-jose/commit/a7746ecd4950f85a393136e449a91dac62b5c429","name":"Introducing commit a7746ec in potatosalad/erlang-jose","tags":["related"]},{"url":"https://github.com/potatosalad/erlang-jose/commit/857eb8e7f2d33e2c9ca2189e77226561cacaf2ad","name":"Fix commit 857eb8e in potatosalad/erlang-jose","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"LOCAL","baseScore":6.9,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-409","description":"CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-10-26T19:53:16.336Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*","versionEndExcluding":"1.11.13","versionStartIncluding":"1.0.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Andrew Bennett"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-130","descriptions":[{"lang":"en","value":"CAPEC-130 Excessive Allocation"}]}],"source":{"discovery":"EXTERNAL"},"workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Reject JWE tokens that carry a <code>zip</code> header before passing them to <code>jose_jwe:block_decrypt/2</code>. DEFLATE compression is rarely used in legitimate JWE traffic, so untrusted tokens whose protected header contains <code>zip: DEF</code> can be inspected and filtered out before decryption.</p>"},{"base64":false,"type":"text/markdown","value":"Reject JWE tokens that carry a `zip` header before passing them to `jose_jwe:block_decrypt/2`. DEFLATE compression is rarely used in legitimate JWE traffic, so untrusted tokens whose protected header contains `zip: DEF` can be inspected and filtered out before decryption."}],"value":"Reject JWE tokens that carry a zip header before passing them to jose_jwe:block_decrypt/2. DEFLATE compression is rarely used in legitimate JWE traffic, so untrusted tokens whose protected header contains zip: DEF can be inspected and filtered out before decryption."}]}}}}