CVE-2026-49755

{"id": "CVE-2026-49755", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-49755", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-08T16:49:57.977214Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "affectedData": [{"cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "repo": "https://github.com/wojtekmach/req", "vendor": "wojtekmach", "modules": ["'Elixir.Req.Steps'"], "product": "req", "versions": [{"status": "affected", "version": "0.1.0", "lessThan": "0.6.1", "versionType": "semver"}], "packageURL": "pkg:hex/req", "packageName": "req", "programFiles": ["lib/req/steps.ex"], "collectionURL": "https://repo.hex.pm", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Req.Steps':decode_body/1"}, {"name": "'Elixir.Req.Steps':decompress_body/1"}]}, {"cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "repo": "https://github.com/wojtekmach/req.git", "vendor": "wojtekmach", "modules": ["'Elixir.Req.Steps'"], "product": "req", "versions": [{"status": "affected", "version": "e37753741cbdc725e6aba3d977b380163bfc0ecb", "lessThan": "84977e5b1a83f26e749d55ad06e3625464af4e8d", "versionType": "git"}], "packageURL": "pkg:github/wojtekmach/req", "packageName": "wojtekmach/req", "programFiles": ["lib/req/steps.ex"], "collectionURL": "https://github.com", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Req.Steps':decode_body/1"}, {"name": "'Elixir.Req.Steps':decompress_body/1"}]}]}], "published": "2026-06-08T16:16:43.860", "references": [{"url": "https://cna.erlef.org/cves/CVE-2026-49755.html", "tags": ["Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/wojtekmach/req/commit/84977e5b1a83f26e749d55ad06e3625464af4e8d", "tags": ["Patch"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/wojtekmach/req/security/advisories/GHSA-655f-mp8p-96gv", "tags": ["Vendor Advisory", "Exploit", "Patch"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://osv.dev/vulnerability/EEF-CVE-2026-49755", "tags": ["Third Party Advisory", "Patch", "Mitigation"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/wojtekmach/req/security/advisories/GHSA-655f-mp8p-96gv", "tags": ["Vendor Advisory", "Exploit", "Patch"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "description": [{"lang": "en", "value": "CWE-409"}]}], "descriptions": [{"lang": "en", "value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in wojtekmach Req allows attacker-controlled HTTP servers to exhaust memory in a Req client via decompression-bomb response bodies.\n\nReq's default response pipeline includes Req.Steps.decode_body/1 and Req.Steps.decompress_body/1 in lib/req/steps.ex. decode_body/1 dispatches on the server-supplied content-type (or URL extension) and calls :zip.extract(body, [:memory]) for application/zip, :erl_tar.extract({:binary, body}, [:memory]) for application/x-tar, and :erl_tar.extract({:binary, body}, [:memory, :compressed]) for application/gzip / .tgz. Each returns the full decompressed archive contents as a [{name, bytes}] list in memory, with no per-entry or total size cap. decompress_body/1 walks the content-encoding header and chains :zlib/:brotli/:ezstd decoders, so a response advertising content-encoding: gzip, gzip, gzip inflates through multiple layers without bound.\n\nBoth steps are enabled by default, no caller opt-in is required, and the attacker controls the content-type and content-encoding headers on their own server (or on any host reached via Req's automatic redirect following). A sub-megabyte response can expand to multiple gigabytes on the victim, crashing the BEAM process.\n\nThis issue affects req: from 0.1.0 before 0.6.1."}, {"lang": "es", "value": "La vulnerabilidad de manejo inadecuado de datos altamente comprimidos (amplificaci\u00f3n de datos) en wojtekmach Req permite a los servidores HTTP controlados por el atacante agotar la memoria en un cliente Req mediante cuerpos de respuesta de bomba de descompresi\u00f3n.\n\nLa pipeline de respuesta predeterminada de Req incluye Req.Steps.decode_body/1 y Req.Steps.decompress_body/1 en lib/req/steps.ex. decode_body/1 despacha seg\u00fan el content-type proporcionado por el servidor (o extensi\u00f3n de URL) y llama a :zip.extract(body, [:memory]) para application/zip, a :erl_tar.extract({:binary, body}, [:memory]) para application/x-tar, y a :erl_tar.extract({:binary, body}, [:memory, :compressed]) para application/gzip / .tgz. Cada uno devuelve el contenido completo del archivo descomprimido como una lista [{name, bytes}] en memoria, sin l\u00edmite de tama\u00f1o por entrada o total. decompress_body/1 recorre el encabezado content-encoding y encadena decodificadores :zlib/:brotli/:ezstd, por lo que una respuesta que anuncia content-encoding: gzip, gzip, gzip se infla a trav\u00e9s de m\u00faltiples capas sin l\u00edmite.\n\nAmbos pasos est\u00e1n habilitados por defecto, no se requiere la participaci\u00f3n del llamador, y el atacante controla los encabezados content-type y content-encoding en su propio servidor (o en cualquier host alcanzado a trav\u00e9s del seguimiento autom\u00e1tico de redirecciones de Req). Una respuesta de menos de un megabyte puede expandirse a m\u00faltiples gigabytes en la v\u00edctima, colapsando el proceso BEAM.\n\nEste problema afecta a req: desde 0.1.0 antes de 0.6.1."}], "lastModified": "2026-08-18T15:46:34.387", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C85D450B-D8C8-46E9-8AEC-6DBAECE8CAF4", "versionEndExcluding": "0.6.1", "versionStartIncluding": "0.1.0"}], "operator": "OR"}]}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}