{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43970", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-05-04T18:23:25.574Z", "datePublished": "2026-05-13T18:43:11.640Z", "dateUpdated": "2026-05-13T18:43:11.640Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["cow_spdy"], "packageName": "cowlib", "packageURL": "pkg:hex/cowlib", "product": "cowlib", "programFiles": ["src/cow_spdy.erl"], "programRoutines": [{"name": "cow_spdy:parse/2"}, {"name": "cow_spdy:inflate/2"}, {"name": "cow_spdy:parse_headers/2"}, {"name": "cow_spdy:parse_headers/4"}], "repo": "https://github.com/ninenines/cowlib", "vendor": "ninenines", "versions": [{"lessThan": "2.16.1", "status": "affected", "version": "0.1.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["cow_spdy"], "packageName": "ninenines/cowlib", "packageURL": "pkg:github/ninenines/cowlib", "product": "cowlib", "programFiles": ["src/cow_spdy.erl"], "programRoutines": [{"name": "cow_spdy:parse/2"}, {"name": "cow_spdy:inflate/2"}, {"name": "cow_spdy:parse_headers/2"}, {"name": "cow_spdy:parse_headers/4"}], "repo": "https://github.com/ninenines/cowlib", "vendor": "ninenines", "versions": [{"lessThan": "16aad3fb9f81f5cda4d1706ff0c54237c619c282", "status": "affected", "version": "fad5c0049df278cc498b6cdb519b09e845a070a8", "versionType": "git"}]}], "configurations": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>The application must use <tt>cow_spdy:parse/2</tt> to parse SPDY frames from an untrusted peer. cowboy itself does not use <tt>cow_spdy</tt>; only direct callers of the <tt>cow_spdy</tt> API are affected.</p>"}], "value": "The application must use cow_spdy:parse/2 to parse SPDY frames from an untrusted peer. cowboy itself does not use cow_spdy; only direct callers of the cow_spdy API are affected."}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.16.1", "versionStartIncluding": "0.1.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "credits": [{"lang": "en", "type": "finder", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Lo\u00efc Hoguin"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion.</p><p><tt>cow_spdy:inflate/2</tt> in cowlib passes peer-supplied compressed bytes directly to <tt>zlib:inflate/2</tt> with no output size bound. The SPDY header compression dictionary (<tt>?ZDICT</tt>) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for <tt>syn_stream</tt>, <tt>syn_reply</tt>, and <tt>headers</tt> frame types are all affected via <tt>cow_spdy:parse_headers/2</tt>.</p><p>This issue affects cowlib from 0.1.0 before 2.16.1.</p>"}], "value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion.\n\ncow_spdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for syn_stream, syn_reply, and headers frame types are all affected via cow_spdy:parse_headers/2.\n\nThis issue affects cowlib from 0.1.0 before 2.16.1."}], "impacts": [{"capecId": "CAPEC-130", "descriptions": [{"lang": "en", "value": "CAPEC-130 Excessive Allocation"}]}], "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-409", "description": "CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-05-13T18:43:11.640Z"}, "references": [{"tags": ["related", "third-party-advisory"], "url": "https://cna.erlef.org/cves/CVE-2026-43970.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43970"}, {"tags": ["patch"], "url": "https://github.com/ninenines/cowlib/commit/16aad3fb9f81f5cda4d1706ff0c54237c619c282"}], "solutions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Upgrade to cowlib 2.16.1 or later, in which the <tt>cow_spdy</tt> module has been removed entirely. No patched version of <tt>cow_spdy</tt> will be provided. Migrate away from SPDY, which has been deprecated since 2015 in favour of HTTP/2.</p>"}], "value": "Upgrade to cowlib 2.16.1 or later, in which the cow_spdy module has been removed entirely. No patched version of cow_spdy will be provided. Migrate away from SPDY, which has been deprecated since 2015 in favour of HTTP/2."}], "source": {"discovery": "EXTERNAL"}, "title": "Decompression Bomb in cow_spdy:inflate/2 Allows Memory Exhaustion via Crafted SPDY Frame", "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion.\n\ncow_spdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for syn_stream, syn_reply, and headers frame types are all affected via cow_spdy:parse_headers/2.\n\nThis issue affects cowlib from 0.1.0 before 2.16.1."}], "id": "CVE-2026-43970", "lastModified": "2026-05-13T19:17:25.440", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-05-13T19:17:25.440", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-43970.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/ninenines/cowlib/commit/16aad3fb9f81f5cda4d1706ff0c54237c619c282"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43970"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-409"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

{}

{}