{"api_version":"1","generated_at":"2026-09-08T09:13:33+00:00","cve":"CVE-2026-66357","urls":{"html":"https://cve.report/CVE-2026-66357","api":"https://cve.report/api/cve/CVE-2026-66357.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-66357","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-66357"},"summary":{"title":"inets,httpd:HTTP Request Smuggling via obs-fold Header Continuation","description":"httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved.\n\nThis issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.","state":"PUBLISHED","assigner":"EEF","published_at":"2026-09-01 15:17:23","updated_at":"2026-09-08 01:17:51"},"problem_types":["CWE-444","CWE-444 CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')"],"metrics":[{"version":"4.0","source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","type":"Secondary","score":"8.3","severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/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","data":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/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","baseScore":8.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"8.3","severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/SA:N","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.3,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"}}],"references":[{"url":"https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qf","name":"https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qf","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85b","name":"https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85b","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4","name":"https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3","name":"https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://cna.erlef.org/cves/CVE-2026-66357.html","name":"https://cna.erlef.org/cves/CVE-2026-66357.html","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-66357","name":"https://osv.dev/vulnerability/EEF-CVE-2026-66357","refsource":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66357","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66357","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Erlang","product":"OTP","version":"unknown 17.0 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 17.0 27.3.4.17 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 28.0 28.5.0.6 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 29.0 29.0.6 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"unknown 5.10 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 5.10 9.3.2.7 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 9.4 9.6.2.3 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 9.7 9.7.2 otp","platforms":[]},{"source":"CNA","vendor":"Erlang","product":"OTP","version":"affected 84adefa331c4159d432d22840663c38f155cd4c1 * git","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Lukas Backström / Erlang Solutions","lang":"en"},{"source":"CNA","value":"Konrad Pietrzak / Ericsson","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"66357","cve":"CVE-2026-66357","epss":"0.003280000","percentile":"0.253810000","score_date":"2026-09-03","updated_at":"2026-09-04 00:08:06"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-66357","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-09-01T15:56:00.806246Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-01T15:56:07.942Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","packageName":"otp","packageURL":"pkg:software-id/erlang.org/otp","product":"OTP","vendor":"Erlang","versions":[{"lessThan":"17.0","status":"unknown","version":"0","versionType":"otp"},{"lessThan":"27.3.4.17","status":"affected","version":"17.0","versionType":"otp"},{"lessThan":"28.5.0.6","status":"affected","version":"28.0","versionType":"otp"},{"lessThan":"29.0.6","status":"affected","version":"29.0","versionType":"otp"}]},{"cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","packageName":"inets","packageURL":"pkg:otp/inets","product":"OTP","repo":"https://github.com/erlang/otp","vendor":"Erlang","versions":[{"lessThan":"5.10","status":"unknown","version":"0","versionType":"otp"},{"lessThan":"9.3.2.7","status":"affected","version":"5.10","versionType":"otp"},{"lessThan":"9.6.2.3","status":"affected","version":"9.4","versionType":"otp"},{"lessThan":"9.7.2","status":"affected","version":"9.7","versionType":"otp"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","packageName":"erlang/otp","packageURL":"pkg:github/erlang/otp","product":"OTP","repo":"https://github.com/erlang/otp","vendor":"Erlang","versions":[{"changes":[{"at":"220d618d2479a7180b4a06d0c5aacfaa4af4a85b","status":"unaffected"},{"at":"273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3","status":"unaffected"},{"at":"e640d599287d2eba919e6f13b91f042d7dbe6ff4","status":"unaffected"}],"lessThan":"*","status":"affected","version":"84adefa331c4159d432d22840663c38f155cd4c1","versionType":"git"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"27.3.4.17","vulnerable":true},{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"28.5.0.6","versionStartIncluding":"28.0","vulnerable":true},{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"29.0.6","versionStartIncluding":"29.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Lukas Backström / Erlang Solutions"},{"lang":"en","type":"remediation developer","value":"Konrad Pietrzak / Ericsson"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"

httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved.

\n

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

"},{"base64":false,"type":"text/markdown","value":"httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved.\n\nThis issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown."}],"value":"httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved.\n\nThis issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown."}],"impacts":[{"capecId":"CAPEC-33","descriptions":[{"lang":"en","value":"CAPEC-33 HTTP Request Smuggling"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.3,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-444","description":"CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-08T01:08:00.943Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory"],"url":"https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qf"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-66357.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-66357"},{"tags":["patch"],"url":"https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85b"},{"tags":["patch"],"url":"https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3"},{"tags":["patch"],"url":"https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4"}],"source":{"discovery":"UNKNOWN"},"title":"inets,httpd:HTTP Request Smuggling via obs-fold Header Continuation"}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-66357","datePublished":"2026-09-01T14:40:50.526Z","dateReserved":"2026-08-17T20:00:02.207Z","dateUpdated":"2026-09-08T01:08:00.943Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-01 15:17:23","lastModifiedDate":"2026-09-08 01:17:51","problem_types":["CWE-444","CWE-444 CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')"],"metrics":{"cvssMetricV40":[{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/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","baseScore":8.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-01T15:56:00.806246Z","id":"CVE-2026-66357","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"66357","Ordinal":"1","Title":"inets,httpd:HTTP Request Smuggling via obs-fold Header Continuat","CVE":"CVE-2026-66357","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"66357","Ordinal":"1","NoteData":"httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved.\n\nThis issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.","Type":"Description","Title":"inets,httpd:HTTP Request Smuggling via obs-fold Header Continuat"}]}}}