{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-56814", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-06-23T12:29:02.507Z", "datePublished": "2026-07-10T11:14:35.574Z", "dateUpdated": "2026-07-10T14:41:43.299Z" }, "containers": { "cna": { "affected": [ { "collectionURL": "https://repo.hex.pm", "cpes": [ "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "modules": [ "'Elixir.Plug.Parsers.MULTIPART'" ], "packageName": "plug", "packageURL": "pkg:hex/plug", "product": "plug", "programFiles": [ "lib/plug/parsers/multipart.ex" ], "programRoutines": [ { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart/2" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_headers/5" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_body/4" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_file/4" } ], "repo": "https://github.com/elixir-plug/plug", "vendor": "elixir-plug", "versions": [ { "lessThan": "1.16.6", "status": "affected", "version": "1.4.0", "versionType": "semver" }, { "lessThan": "1.17.4", "status": "affected", "version": "1.17.0", "versionType": "semver" }, { "lessThan": "1.18.5", "status": "affected", "version": "1.18.0", "versionType": "semver" }, { "lessThan": "1.19.5", "status": "affected", "version": "1.19.0", "versionType": "semver" }, { "lessThan": "1.20.3", "status": "affected", "version": "1.20.0", "versionType": "semver" } ] }, { "collectionURL": "https://github.com", "cpes": [ "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "modules": [ "'Elixir.Plug.Parsers.MULTIPART'" ], "packageName": "elixir-plug/plug", "packageURL": "pkg:github/elixir-plug/plug", "product": "plug", "programFiles": [ "lib/plug/parsers/multipart.ex" ], "programRoutines": [ { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart/2" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_headers/5" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_body/4" }, { "name": "'Elixir.Plug.Parsers.MULTIPART':parse_multipart_file/4" } ], "repo": "https://github.com/elixir-plug/plug", "vendor": "elixir-plug", "versions": [ { "changes": [ { "at": "981597d3a4271ede64373c7a731702a42c500dd6", "status": "unaffected" }, { "at": "56edca2ce35fe5589cd581644d8a4493fa5f484e", "status": "unaffected" }, { "at": "0ee8afcc61466dc5f7a8f048d0632c899165b81f", "status": "unaffected" }, { "at": "cae36053350e5215a4e0ca33cd130af9c5fc6364", "status": "unaffected" }, { "at": "f7effaed811c00b5f5bf817936bfd9c5df27b7dc", "status": "unaffected" }, { "at": "df97d3f17f808a9916a7700a701fb85314559d56", "status": "unaffected" } ], "lessThan": "*", "status": "affected", "version": "c52b2f32c90bccd718202bafccb5f95594e30183", "versionType": "git" } ] } ], "cpeApplicability": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.16.6", "versionStartIncluding": "1.4.0", "vulnerable": true }, { "criteria": "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.17.4", "versionStartIncluding": "1.17.0", "vulnerable": true }, { "criteria": "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.18.5", "versionStartIncluding": "1.18.0", "vulnerable": true }, { "criteria": "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.19.5", "versionStartIncluding": "1.19.0", "vulnerable": true }, { "criteria": "cpe:2.3:a:elixir-plug:plug:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.20.3", "versionStartIncluding": "1.20.0", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "AND" } ], "credits": [ { "lang": "en", "type": "finder", "value": "Peter Ullrich" }, { "lang": "en", "type": "analyst", "value": "Jonatan Männchen" }, { "lang": "en", "type": "remediation developer", "value": "José Valim" } ], "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

Plug.Parsers.MULTIPART, the multipart request-body parser used to handle file uploads and multipart forms, does not enforce its :length budget against all consumed resources, allowing an unauthenticated remote attacker to cause denial of service. The parser charges the :length limit only for part body bytes; part header bytes are never counted, and a part with an empty body costs zero.

Because every part whose Content-Disposition carries a non-empty filename creates a fresh temporary file (via Plug.Upload) and retains a Plug.Upload struct for the duration of the request, an attacker can send a single request composed of many empty-body file parts. Such a request stays well under the configured :length limit (8,000,000 bytes by default) while creating one temporary file per part, leading to inode and disk exhaustion and unbounded memory growth. Any application using Plug.Parsers with the :multipart parser is affected, and no authentication is required, only reachability of a multipart endpoint over HTTP.

This vulnerability is associated with program files lib/plug/parsers/multipart.ex and program routines Plug.Parsers.MULTIPART.parse_multipart/2, Plug.Parsers.MULTIPART.parse_multipart_headers/5, Plug.Parsers.MULTIPART.parse_multipart_body/4, and Plug.Parsers.MULTIPART.parse_multipart_file/4.

This issue affects plug: from 1.4.0 before 1.16.6, from 1.17.0 before 1.17.4, from 1.18.0 before 1.18.5, from 1.19.0 before 1.19.5, and from 1.20.0 before 1.20.3.

" } ], "value": "Plug.Parsers.MULTIPART, the multipart request-body parser used to handle file uploads and multipart forms, does not enforce its :length budget against all consumed resources, allowing an unauthenticated remote attacker to cause denial of service. The parser charges the :length limit only for part body bytes; part header bytes are never counted, and a part with an empty body costs zero.\n\nBecause every part whose Content-Disposition carries a non-empty filename creates a fresh temporary file (via Plug.Upload) and retains a Plug.Upload struct for the duration of the request, an attacker can send a single request composed of many empty-body file parts. Such a request stays well under the configured :length limit (8,000,000 bytes by default) while creating one temporary file per part, leading to inode and disk exhaustion and unbounded memory growth. Any application using Plug.Parsers with the :multipart parser is affected, and no authentication is required, only reachability of a multipart endpoint over HTTP.\n\nThis vulnerability is associated with program files lib/plug/parsers/multipart.ex and program routines Plug.Parsers.MULTIPART.parse_multipart/2, Plug.Parsers.MULTIPART.parse_multipart_headers/5, Plug.Parsers.MULTIPART.parse_multipart_body/4, and Plug.Parsers.MULTIPART.parse_multipart_file/4.\n\nThis issue affects plug: from 1.4.0 before 1.16.6, from 1.17.0 before 1.17.4, from 1.18.0 before 1.18.5, from 1.19.0 before 1.19.5, and from 1.20.0 before 1.20.3." } ], "impacts": [ { "capecId": "CAPEC-130", "descriptions": [ { "lang": "en", "value": "CAPEC-130 Excessive Allocation" } ] } ], "metrics": [ { "cvssV4_0": { "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 6.9, "baseSeverity": "MEDIUM", "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:N/VI:N/VA:L/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-770", "description": "CWE-770 Allocation of Resources Without Limits or Throttling", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-07-10T14:41:43.299Z" }, "references": [ { "tags": [ "vendor-advisory", "related" ], "url": "https://github.com/elixir-plug/plug/security/advisories/GHSA-95qv-c9g9-rm63" }, { "tags": [ "related" ], "url": "https://cna.erlef.org/cves/CVE-2026-56814.html" }, { "tags": [ "related" ], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-56814" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/981597d3a4271ede64373c7a731702a42c500dd6" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/56edca2ce35fe5589cd581644d8a4493fa5f484e" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/0ee8afcc61466dc5f7a8f048d0632c899165b81f" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/cae36053350e5215a4e0ca33cd130af9c5fc6364" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/f7effaed811c00b5f5bf817936bfd9c5df27b7dc" }, { "tags": [ "patch" ], "url": "https://github.com/elixir-plug/plug/commit/df97d3f17f808a9916a7700a701fb85314559d56" } ], "source": { "discovery": "EXTERNAL" }, "title": "Plug: multipart :length limit is not charged for part headers, enabling unbounded temp-file creation (denial of service)", "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-07-10T14:03:11.744626Z", "id": "CVE-2026-56814", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-10T14:03:28.156Z" } } ] } }