{"id":"CVE-2026-8468","state":"PUBLISHED","title":"Unbounded buffer accumulation in multipart header parsing causes denial of service in plug","description":"Allocation of Resources Without Limits or Throttling vulnerability in plug_project plug allows denial of service via unbounded buffer accumulation in multipart header parsing.\n\n'Elixir.Plug.Conn':read_part_headers/2 in lib/plug/conn.ex does not obey its :length parameter. There is no upper bound on the size of the accumulated buffer. By contrast, the sibling function read_part_body has an explicit byte_size(acc) > length guard that stops accumulation once a limit is reached. No such guard exists in read_part_headers. An unauthenticated remote attacker can exhaust server memory by sending a crafted multipart/form-data request, causing a denial of service.\n\nThis issue affects plug from 1.4.0 before 1.15.4, 1.16.3, 1.17.1, 1.18.2, and 1.19.2.","publishedAt":"2026-05-14T10:29:51.062Z","updatedAt":"2026-05-27T15:41:29.241Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"EEF"},"assigner":"EEF","products":["elixir-plug plug"],"affected":[{"vendor":"elixir-plug","product":"plug","packageName":"plug","packageURL":"pkg:hex/plug","defaultStatus":"unaffected","versions":[{"version":"1.4.0","status":"affected","lessThan":"1.15.4","versionType":"semver"},{"version":"1.16.0","status":"affected","lessThan":"1.16.3","versionType":"semver"},{"version":"1.17.0","status":"affected","lessThan":"1.17.1","versionType":"semver"},{"version":"1.18.0","status":"affected","lessThan":"1.18.2","versionType":"semver"},{"version":"1.19.0","status":"affected","lessThan":"1.19.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*"],"modules":["Elixir.Plug.Conn"],"programFiles":["lib/plug/conn.ex"],"programRoutines":[{"name":"'Elixir.Plug.Conn':read_part_headers/2"}],"repo":"https://github.com/elixir-plug/plug"},{"vendor":"elixir-plug","product":"plug","packageName":"elixir-plug/plug","packageURL":"pkg:github/elixir-plug/plug","defaultStatus":"unaffected","versions":[{"version":"c52b2f32c90bccd718202bafccb5f95594e30183","status":"affected","lessThan":"*","changes":[{"at":"2cb7958d33030aa826b0c7404375844d4593d43a","status":"unaffected"},{"at":"aa69c5ece99c40ded88b8c6581ecc86664b0b734","status":"unaffected"},{"at":"d5dfffe25e975585227b1b85d247b0d14164bc45","status":"unaffected"},{"at":"df812a1527bae9e941965e897308a2b8bbf83a94","status":"unaffected"},{"at":"33858427c7f2737d560a2e40a0c9a9270d77d1d7","status":"unaffected"}],"versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*"],"modules":["Elixir.Plug.Conn"],"programFiles":["lib/plug/conn.ex"],"programRoutines":[{"name":"'Elixir.Plug.Conn':read_part_headers/2"}],"repo":"https://github.com/elixir-plug/plug"}],"references":["https://github.com/elixir-plug/plug/security/advisories/GHSA-468c-vq7p-gh64","https://cna.erlef.org/cves/CVE-2026-8468.html","https://osv.dev/vulnerability/EEF-CVE-2026-8468","https://cna.erlef.org/cves/CVE-2026-8466.html","https://github.com/elixir-plug/plug/commit/2cb7958d33030aa826b0c7404375844d4593d43a","https://github.com/elixir-plug/plug/commit/aa69c5ece99c40ded88b8c6581ecc86664b0b734","https://github.com/elixir-plug/plug/commit/d5dfffe25e975585227b1b85d247b0d14164bc45","https://github.com/elixir-plug/plug/commit/df812a1527bae9e941965e897308a2b8bbf83a94","https://github.com/elixir-plug/plug/commit/33858427c7f2737d560a2e40a0c9a9270d77d1d7"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/8xxx/CVE-2026-8468.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-8468","state":"PUBLISHED","datePublished":"2026-05-14T10:29:51.062Z","dateUpdated":"2026-05-27T15:41:29.241Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-05-13T11:44:42.164Z"},"containers":{"cna":{"title":"Unbounded buffer accumulation in multipart header parsing causes denial of service in plug","descriptions":[{"lang":"en","value":"Allocation of Resources Without Limits or Throttling vulnerability in plug_project plug allows denial of service via unbounded buffer accumulation in multipart header parsing.\n\n'Elixir.Plug.Conn':read_part_headers/2 in lib/plug/conn.ex does not obey its :length parameter. There is no upper bound on the size of the accumulated buffer. By contrast, the sibling function read_part_body has an explicit byte_size(acc) > length guard that stops accumulation once a limit is reached. No such guard exists in read_part_headers. An unauthenticated remote attacker can exhaust server memory by sending a crafted multipart/form-data request, causing a denial of service.\n\nThis issue affects plug from 1.4.0 before 1.15.4, 1.16.3, 1.17.1, 1.18.2, and 1.19.2."}],"affected":[{"vendor":"elixir-plug","product":"plug","packageName":"plug","packageURL":"pkg:hex/plug","defaultStatus":"unaffected","versions":[{"version":"1.4.0","status":"affected","lessThan":"1.15.4","versionType":"semver"},{"version":"1.16.0","status":"affected","lessThan":"1.16.3","versionType":"semver"},{"version":"1.17.0","status":"affected","lessThan":"1.17.1","versionType":"semver"},{"version":"1.18.0","status":"affected","lessThan":"1.18.2","versionType":"semver"},{"version":"1.19.0","status":"affected","lessThan":"1.19.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*"],"modules":["Elixir.Plug.Conn"],"programFiles":["lib/plug/conn.ex"],"programRoutines":[{"name":"'Elixir.Plug.Conn':read_part_headers/2"}],"repo":"https://github.com/elixir-plug/plug"},{"vendor":"elixir-plug","product":"plug","packageName":"elixir-plug/plug","packageURL":"pkg:github/elixir-plug/plug","defaultStatus":"unaffected","versions":[{"version":"c52b2f32c90bccd718202bafccb5f95594e30183","status":"affected","lessThan":"*","changes":[{"at":"2cb7958d33030aa826b0c7404375844d4593d43a","status":"unaffected"},{"at":"aa69c5ece99c40ded88b8c6581ecc86664b0b734","status":"unaffected"},{"at":"d5dfffe25e975585227b1b85d247b0d14164bc45","status":"unaffected"},{"at":"df812a1527bae9e941965e897308a2b8bbf83a94","status":"unaffected"},{"at":"33858427c7f2737d560a2e40a0c9a9270d77d1d7","status":"unaffected"}],"versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*"],"modules":["Elixir.Plug.Conn"],"programFiles":["lib/plug/conn.ex"],"programRoutines":[{"name":"'Elixir.Plug.Conn':read_part_headers/2"}],"repo":"https://github.com/elixir-plug/plug"}],"references":[{"url":"https://github.com/elixir-plug/plug/security/advisories/GHSA-468c-vq7p-gh64","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-8468.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-8468","tags":["related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-8466.html","tags":["related"]},{"url":"https://github.com/elixir-plug/plug/commit/2cb7958d33030aa826b0c7404375844d4593d43a","tags":["patch"]},{"url":"https://github.com/elixir-plug/plug/commit/aa69c5ece99c40ded88b8c6581ecc86664b0b734","tags":["patch"]},{"url":"https://github.com/elixir-plug/plug/commit/d5dfffe25e975585227b1b85d247b0d14164bc45","tags":["patch"]},{"url":"https://github.com/elixir-plug/plug/commit/df812a1527bae9e941965e897308a2b8bbf83a94","tags":["patch"]},{"url":"https://github.com/elixir-plug/plug/commit/33858427c7f2737d560a2e40a0c9a9270d77d1d7","tags":["patch"]}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.2,"baseSeverity":"HIGH","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/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"},"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":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-05-27T15:41:29.241Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>The application must use <tt>Plug.Parsers</tt> with the <tt>:multipart</tt> parser, or otherwise call <tt>Plug.Conn.read_part_headers/2</tt> to process <tt>multipart/form-data</tt> request bodies. Deployments that do not handle multipart uploads are not affected.</p>"}],"value":"The application must use Plug.Parsers with the :multipart parser, or otherwise call Plug.Conn.read_part_headers/2 to process multipart/form-data request bodies. Deployments that do not handle multipart uploads are not affected."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*","versionEndExcluding":"1.15.4","versionStartIncluding":"1.4.0","vulnerable":true},{"criteria":"cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*","versionEndExcluding":"1.16.3","versionStartIncluding":"1.16.0","vulnerable":true},{"criteria":"cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*","versionEndExcluding":"1.17.1","versionStartIncluding":"1.17.0","vulnerable":true},{"criteria":"cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*","versionEndExcluding":"1.18.2","versionStartIncluding":"1.18.0","vulnerable":true},{"criteria":"cpe:2.3:a:plug_project:plug:*:*:*:*:*:*:*:*","versionEndExcluding":"1.19.2","versionStartIncluding":"1.19.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"José Valim"},{"lang":"en","type":"remediation developer","value":"José Valim"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-130","descriptions":[{"lang":"en","value":"CAPEC-130 Excessive Allocation"}]}],"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-14T17:53:52.632415Z","id":"CVE-2026-8468","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-14T17:54:23.302Z"}}]}}}