CVE-2026-7790

{"id": "CVE-2026-7790", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-7790", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-11T18:56:19.590262Z"}}], "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": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/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": "NONE", "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:ninenines:cowlib:*:*:*:*:*:*:*:*"], "repo": "https://github.com/ninenines/cowlib", "vendor": "ninenines", "modules": ["cow_http_te"], "product": "cowlib", "versions": [{"status": "affected", "version": "0.6.0", "lessThan": "2.16.1", "versionType": "semver"}], "packageURL": "pkg:hex/cowlib", "packageName": "cowlib", "programFiles": ["src/cow_http_te.erl"], "collectionURL": "https://repo.hex.pm", "defaultStatus": "unaffected", "programRoutines": [{"name": "cow_http_te:stream_chunked/2"}, {"name": "cow_http_te:chunked_len/4"}]}, {"cpes": ["cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*"], "repo": "https://github.com/ninenines/cowlib", "vendor": "ninenines", "modules": ["cow_http_te"], "product": "cowlib", "versions": [{"status": "affected", "version": "8c0e428b012c59f553a264f285ed89d36f791e3e", "lessThan": "a4b8039ce8c93ab00867ef6b7e888822c09f4369", "versionType": "git"}], "packageURL": "pkg:github/ninenines/cowlib", "packageName": "ninenines/cowlib", "programFiles": ["src/cow_http_te.erl"], "collectionURL": "https://github.com", "defaultStatus": "unaffected", "programRoutines": [{"name": "cow_http_te:stream_chunked/2"}, {"name": "cow_http_te:chunked_len/4"}]}]}], "published": "2026-05-11T19:16:29.477", "references": [{"url": "https://cna.erlef.org/cves/CVE-2026-7790.html", "tags": ["Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/ninenines/cowlib/commit/a4b8039ce8c93ab00867ef6b7e888822c09f4369", "tags": ["Patch"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://osv.dev/vulnerability/EEF-CVE-2026-7790", "tags": ["Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "description": [{"lang": "en", "value": "CWE-400"}]}], "descriptions": [{"lang": "en", "value": "Uncontrolled Resource Consumption vulnerability in ninenines cowlib (cow_http_te module) allows Excessive Allocation.\n\nThe chunked transfer-encoding parser in cow_http_te accepts an unbounded number of hex digits in the chunk-size field. Each digit causes a bignum multiplication (Len * 16 + digit), so parsing N hex digits requires O(N\u00b2) CPU work and O(N) memory. Additionally, when input is drip-fed, the parser discards the accumulated length on each partial read and restarts from zero on resumption, raising the cost to O(N\u00b3). An unauthenticated remote attacker can exploit this by sending an HTTP/1.1 request with Transfer-Encoding: chunked and a very long chunk-size hex string to cause denial of service through CPU exhaustion and memory amplification.\n\nThis vulnerability is associated with program file src/cow_http_te.erl and program routines cow_http_te:stream_chunked/2, cow_http_te:chunked_len/4.\n\nThis issue affects cowlib: from 0.6.0 before 2.16.1."}, {"lang": "es", "value": "Una vulnerabilidad de consumo de recursos no controlado en ninenines cowlib (m\u00f3dulo cow_http_te) permite una asignaci\u00f3n excesiva.\n\nEl analizador de codificaci\u00f3n de transferencia por bloques en cow_http_te acepta un n\u00famero ilimitado de d\u00edgitos hexadecimales en el campo de tama\u00f1o de bloque (\u2019chunk-size\u2019). Cada d\u00edgito provoca una multiplicaci\u00f3n de n\u00famero grande (\u2019bignum\u2019) (Len * 16 + d\u00edgito), por lo que analizar N d\u00edgitos hexadecimales requiere un trabajo de CPU de O(N\u00b2) y una memoria de O(N). Adem\u00e1s, cuando la entrada se alimenta por goteo, el analizador descarta la longitud acumulada en cada lectura parcial y se reinicia desde cero al reanudarse, elevando el costo a O(N\u00b3). Un atacante remoto no autenticado puede explotar esto enviando una solicitud HTTP/1.1 con Transfer-Encoding: chunked y una cadena hexadecimal de tama\u00f1o de bloque (\u2019chunk-size\u2019) muy larga para causar denegaci\u00f3n de servicio a trav\u00e9s del agotamiento de la CPU y la amplificaci\u00f3n de la memoria.\n\nEsta vulnerabilidad est\u00e1 asociada con el archivo de programa src/cow_http_te.erl y las rutinas de programa cow_http_te:stream_chunked/2, cow_http_te:chunked_len/4.\n\nEste problema afecta a cowlib: desde 0.6.0 antes de 2.16.1."}], "lastModified": "2026-10-26T18:10:00.173", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F6362B55-F0FF-4196-984D-99512487861D", "versionEndExcluding": "2.16.1", "versionStartIncluding": "0.6.0"}], "operator": "OR"}]}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}