{"id":"CVE-2026-49754","state":"PUBLISHED","title":"HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation","description":"Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client (HTTP/2 CONTINUATION flood).\n\nWhen Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, the unparsed header-block fragment is parked in conn.headers_being_processed, and every subsequent CONTINUATION frame on that stream is appended to the accumulator. Nothing in the receive path caps the accumulator: there is no per-stream size limit, no CONTINUATION frame-count limit, and max_header_list_size is only enforced on outgoing requests, never on inbound header blocks (its default is :infinity).\n\nA malicious or compromised HTTP/2 server can stream an endless sequence of CONTINUATION frames (each up to the peer-advertised SETTINGS_MAX_FRAME_SIZE) and drive the client's iolist to arbitrary size, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient.\n\nThis issue affects mint: from 0.1.0 before 1.9.0.","publishedAt":"2026-06-02T14:15:14.951Z","updatedAt":"2026-06-02T19:14:33.100Z","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-mint mint"],"affected":[{"vendor":"elixir-mint","product":"mint","packageName":"mint","packageURL":"pkg:hex/mint","defaultStatus":"unaffected","versions":[{"version":"0.1.0","status":"affected","lessThan":"1.9.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP2'"],"programFiles":["lib/mint/http2.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP2':handle_continuation/3"},{"name":"'Elixir.Mint.HTTP2':handle_headers/3"}],"repo":"https://github.com/elixir-mint/mint"},{"vendor":"elixir-mint","product":"mint","packageName":"elixir-mint/mint","packageURL":"pkg:github/elixir-mint/mint","defaultStatus":"unaffected","versions":[{"version":"596ca4304504be68939c4929e0831557097962b8","status":"affected","lessThan":"b662d127d3028b5426c88d4c9cc7fe430491a10b","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP2'"],"programFiles":["lib/mint/http2.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP2':handle_continuation/3"},{"name":"'Elixir.Mint.HTTP2':handle_headers/3"}],"repo":"https://github.com/elixir-mint/mint.git"}],"references":["https://github.com/elixir-mint/mint/security/advisories/GHSA-2p26-p43x-fhp8","https://cna.erlef.org/cves/CVE-2026-49754.html","https://osv.dev/vulnerability/EEF-CVE-2026-49754","https://github.com/elixir-mint/mint/commit/b662d127d3028b5426c88d4c9cc7fe430491a10b"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49754.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49754","state":"PUBLISHED","datePublished":"2026-06-02T14:15:14.951Z","dateUpdated":"2026-06-02T19:14:33.100Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-06-01T13:45:22.448Z"},"containers":{"cna":{"title":"HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation","descriptions":[{"lang":"en","value":"Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client (HTTP/2 CONTINUATION flood).\n\nWhen Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, the unparsed header-block fragment is parked in conn.headers_being_processed, and every subsequent CONTINUATION frame on that stream is appended to the accumulator. Nothing in the receive path caps the accumulator: there is no per-stream size limit, no CONTINUATION frame-count limit, and max_header_list_size is only enforced on outgoing requests, never on inbound header blocks (its default is :infinity).\n\nA malicious or compromised HTTP/2 server can stream an endless sequence of CONTINUATION frames (each up to the peer-advertised SETTINGS_MAX_FRAME_SIZE) and drive the client's iolist to arbitrary size, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient.\n\nThis issue affects mint: from 0.1.0 before 1.9.0."}],"affected":[{"vendor":"elixir-mint","product":"mint","packageName":"mint","packageURL":"pkg:hex/mint","defaultStatus":"unaffected","versions":[{"version":"0.1.0","status":"affected","lessThan":"1.9.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP2'"],"programFiles":["lib/mint/http2.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP2':handle_continuation/3"},{"name":"'Elixir.Mint.HTTP2':handle_headers/3"}],"repo":"https://github.com/elixir-mint/mint"},{"vendor":"elixir-mint","product":"mint","packageName":"elixir-mint/mint","packageURL":"pkg:github/elixir-mint/mint","defaultStatus":"unaffected","versions":[{"version":"596ca4304504be68939c4929e0831557097962b8","status":"affected","lessThan":"b662d127d3028b5426c88d4c9cc7fe430491a10b","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP2'"],"programFiles":["lib/mint/http2.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP2':handle_continuation/3"},{"name":"'Elixir.Mint.HTTP2':handle_headers/3"}],"repo":"https://github.com/elixir-mint/mint.git"}],"references":[{"url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-2p26-p43x-fhp8","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-49754.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-49754","tags":["related"]},{"url":"https://github.com/elixir-mint/mint/commit/b662d127d3028b5426c88d4c9cc7fe430491a10b","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":"2026-06-02T19:14:33.100Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*","versionEndExcluding":"1.9.0","versionStartIncluding":"0.1.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Eric Meadows-Jönsson"},{"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>Restrict Mint to HTTP/1 on connections to untrusted servers by passing <tt>protocols: [:http1]</tt> to <tt>'Elixir.Mint.HTTP':connect/4</tt>. This avoids the vulnerable HTTP/2 receive path entirely, at the cost of losing HTTP/2 for those connections.</p>"}],"value":"Restrict Mint to HTTP/1 on connections to untrusted servers by passing protocols: [:http1] to Mint.HTTP.connect/4. This avoids the vulnerable HTTP/2 receive path entirely, at the cost of losing HTTP/2 for those connections."}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-2p26-p43x-fhp8","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-02T18:08:02.308938Z","id":"CVE-2026-49754","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-02T18:08:05.621Z"}}]}}}