{"id":"EEF-CVE-2026-65627","aliases":["CVE-2026-65627","GHSA-wfpv-qxp8-x5gm"],"title":"Decompression bomb via unbounded zlib:inflate in jose_jwe_zip:uncompress/2","titleSource":"OSV","descriptionSource":"OSV","description":"## Summary\n\nImproper 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.\n\n## Workarounds\n\nReject 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.","severity":"medium","score":6.9,"published":"2026-10-26T19:53:16.336Z","modified":"2026-10-26T20:11:07.749Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Hex","name":"jose","sources":[{"name":"OSV · EEF-CVE-2026-65627","url":"https://osv.dev/vulnerability/EEF-CVE-2026-65627"}],"ranges":[{"events":[{"introduced":"1.0.0"},{"fixed":"1.11.13"}],"type":"SEMVER"}],"versions":["1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.10.1","1.11.0","1.11.1","1.11.10","1.11.11","1.11.12","1.11.2","1.11.4","1.11.5","1.11.6","1.11.7","1.11.8","1.11.9","1.2.0","1.3.0","1.4.0","1.4.1","1.4.2","1.5.0","1.5.1","1.5.2","1.6.0","1.6.1","1.7.0","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","1.7.8","1.7.9","1.8.0","1.8.1","1.8.2","1.8.3","1.8.4","1.9.0"],"fixed":["1.11.13"]}],"sourceAffected":[{"ranges":[{"events":[{"introduced":"a7746ecd4950f85a393136e449a91dac62b5c429"},{"fixed":"857eb8e7f2d33e2c9ca2189e77226561cacaf2ad"}],"type":"GIT","repo":"https://github.com/potatosalad/erlang-jose"}],"versions":["1.11.12","1.11.11","1.11.10","1.11.9","1.11.8","1.11.7","1.11.5","1.11.4","1.11.2","1.11.1","1.11.0","1.10.1","1.10.0","1.9.0","1.8.4","1.8.3","1.8.2","1.8.1","1.8.0","1.7.9","1.7.8","1.7.7","1.7.6","1.7.5","1.7.4","1.7.3","1.7.2","1.7.1","1.7.0","1.6.1","1.6.0","1.5.2","1.5.1","1.5.0","1.4.2","1.4.1","1.4.0","1.3.0","1.2.0","1.1.3","1.1.2","1.1.1","1.1.0","1.0.1","1.0.0"]}],"references":["https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-wfpv-qxp8-x5gm","https://cna.erlef.org/cves/CVE-2026-65627.html","https://github.com/potatosalad/erlang-jose/commit/a7746ecd4950f85a393136e449a91dac62b5c429","https://github.com/potatosalad/erlang-jose/commit/857eb8e7f2d33e2c9ca2189e77226561cacaf2ad","https://hex.pm/packages/jose","https://osv.dev/vulnerability/EEF-CVE-2026-65627"],"sources":[{"name":"OSV","id":"EEF-CVE-2026-65627","modified":"2026-10-26T20:11:07.749600993Z","url":"https://osv.dev/vulnerability/EEF-CVE-2026-65627"},{"name":"CVE","id":"CVE-2026-65627","modified":"2026-10-26T19:53:16.336Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-65627"}],"assessments":[{"source":"OSV","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","score":6.9},{"source":"EEF","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","score":6.9}],"products":[{"vendor":"potatosalad","name":"jose","platforms":[],"versions":[{"version":"1.0.0","status":"affected","lessThan":"1.11.13","versionType":"semver"}],"defaultStatus":"unaffected","source":"EEF","url":"https://www.cve.org/CVERecord?id=CVE-2026-65627"},{"vendor":"potatosalad","name":"jose","platforms":[],"versions":[{"version":"a7746ecd4950f85a393136e449a91dac62b5c429","status":"affected","lessThan":"857eb8e7f2d33e2c9ca2189e77226561cacaf2ad","versionType":"git"}],"defaultStatus":"unaffected","source":"EEF","url":"https://www.cve.org/CVERecord?id=CVE-2026-65627"}],"remediation":[{"text":"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.","source":"EEF","url":"https://www.cve.org/CVERecord?id=CVE-2026-65627"}],"kev":{"status":"not-listed","checkedAt":"2026-10-28T20:50:31.340Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}