{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["hackney_h3"],"packageName":"hackney","packageURL":"pkg:hex/hackney","product":"hackney","programFiles":["src/hackney_h3.erl"],"programRoutines":[{"name":"hackney_h3:await_response_loop/6"}],"repo":"https://github.com/benoitc/hackney","vendor":"benoitc","versions":[{"lessThan":"4.0.1","status":"affected","version":"2.0.0","versionType":"semver"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["hackney_h3"],"packageName":"benoitc/hackney","packageURL":"pkg:github/benoitc/hackney","product":"hackney","programFiles":["src/hackney_h3.erl"],"programRoutines":[{"name":"hackney_h3:await_response_loop/6"}],"repo":"https://github.com/benoitc/hackney","vendor":"benoitc","versions":[{"lessThan":"3d25f9fea26c90609de9d64366fedfe5065413bc","status":"affected","version":"0334af206d5099fdf510ed9eda18e34396f065ad","versionType":"git"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The application must use the HTTP/3 transport by calling <tt>hackney_h3</tt> directly or by passing <tt>{transport, h3}</tt> to <tt>hackney:request/5</tt>. The default hackney transport (TCP/TLS) is not affected."}],"value":"The application must use the HTTP/3 transport by calling hackney_h3 directly or by passing {transport, h3} to hackney:request/5. The default hackney transport (TCP/TLS) is not affected."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*","versionEndExcluding":"4.0.1","versionStartIncluding":"2.0.0","vulnerable":true}],"negate":false,"operator":"AND"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Benoit Chesneau"},{"lang":"en","type":"analyst","value":"Jonatan Männchen"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding.<p><tt>hackney_h3:await_response_loop/6</tt> accumulates the HTTP/3 response body in memory without any size cap. The <tt>after Timeout</tt> clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame — it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every <tt>Timeout - 1</tt> ms with <tt>Fin = false</tt> and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.</p><p>This issue affects hackney: from 2.0.0 before 4.0.1.</p>"}],"value":"Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackney_h3:await_response_loop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame — it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every Timeout - 1 ms with Fin = false and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.\n\nThis issue affects hackney: from 2.0.0 before 4.0.1."}],"impacts":[{"capecId":"CAPEC-125","descriptions":[{"lang":"en","value":"CAPEC-125 Flooding"}]}],"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-400","description":"CWE-400 Uncontrolled Resource Consumption","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-25T14:00:42.217Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory","related"],"url":"https://github.com/benoitc/hackney/security/advisories/GHSA-jq4m-q6p2-8gwc"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-47077.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-47077"},{"tags":["patch"],"url":"https://github.com/benoitc/hackney/commit/3d25f9fea26c90609de9d64366fedfe5065413bc"}],"source":{"discovery":"EXTERNAL"},"title":"Unbounded body accumulation in HTTP/3 response loop in hackney","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-47077","datePublished":"2026-05-25T14:00:42.217Z","dateReserved":"2026-05-18T17:28:10.319Z","dateUpdated":"2026-05-25T14:00:42.217Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}