{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-49756", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-06-01T13:45:22.448Z", "datePublished": "2026-06-08T15:20:24.035Z", "dateUpdated": "2026-06-08T16:34:58.505Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Req.Utils'"], "packageName": "req", "packageURL": "pkg:hex/req", "product": "req", "programFiles": ["lib/req/utils.ex"], "programRoutines": [{"name": "'Elixir.Req.Utils':encode_form_part/2"}], "repo": "https://github.com/wojtekmach/req", "vendor": "wojtekmach", "versions": [{"lessThan": "0.6.0", "status": "affected", "version": "0.5.3", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Req.Utils'"], "packageName": "wojtekmach/req", "packageURL": "pkg:github/wojtekmach/req", "product": "req", "programFiles": ["lib/req/utils.ex"], "programRoutines": [{"name": "'Elixir.Req.Utils':encode_form_part/2"}], "repo": "https://github.com/wojtekmach/req.git", "vendor": "wojtekmach", "versions": [{"lessThan": "74506ff2c5addf74df85d79dc726e9b2e264a8ba", "status": "affected", "version": "60253dbe9436cb8e9c738f895032f2e87939b597", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*", "versionEndExcluding": "0.6.0", "versionStartIncluding": "0.5.3", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Wojtek Mach"}, {"lang": "en", "type": "analyst", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in wojtekmach Req allows multipart parameter smuggling via attacker-influenced part metadata.<p><tt>'Elixir.Req.Utils':encode_form_part/2</tt> in <tt>lib/req/utils.ex</tt> builds the per-part headers by interpolating the caller-supplied <tt>name</tt>, <tt>filename</tt>, and <tt>content_type</tt> values directly into the <tt>content-disposition</tt> and <tt>content-type</tt> lines with no escaping or CRLF stripping. A value containing <tt>\"</tt>, <tt>\\r</tt>, or <tt>\\n</tt> closes the surrounding quoted value and starts a new header line; an additional <tt>\\r\\n--&lt;boundary&gt;</tt> terminates the current part and prepends a smuggled part of the attacker's choosing.</p><p>This is reachable through every supported way of supplying a part. It is particularly easy when <tt>value</tt> is a <tt>%File.Stream{}</tt>, because <tt>filename</tt> then defaults to <tt>Path.basename(stream.path)</tt> and POSIX filenames may legitimately contain <tt>\\r</tt> and <tt>\\n</tt>. Any application that forwards user-controlled filenames (or field names / MIME types) through <tt>'Elixir.Req':post/2</tt> with <tt>form_multipart:</tt> lets an attacker inject arbitrary headers into the outgoing multipart body or smuggle additional fields and parts into the request the victim service sends downstream.</p><p>This issue affects req: from 0.5.3 before 0.6.0.</p>"}], "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in wojtekmach Req allows multipart parameter smuggling via attacker-influenced part metadata.\n\nReq.Utils.encode_form_part/2 in lib/req/utils.ex builds the per-part headers by interpolating the caller-supplied name, filename, and content_type values directly into the content-disposition and content-type lines with no escaping or CRLF stripping. A value containing \", \\r, or \\n closes the surrounding quoted value and starts a new header line; an additional \\r\\n--<boundary> terminates the current part and prepends a smuggled part of the attacker's choosing.\n\nThis is reachable through every supported way of supplying a part. It is particularly easy when value is a %File.Stream{}, because filename then defaults to Path.basename(stream.path) and POSIX filenames may legitimately contain \\r and \\n. Any application that forwards user-controlled filenames (or field names / MIME types) through Req.post/2 with form_multipart: lets an attacker inject arbitrary headers into the outgoing multipart body or smuggle additional fields and parts into the request the victim service sends downstream.\n\nThis issue affects req: from 0.5.3 before 0.6.0."}], "impacts": [{"capecId": "CAPEC-33", "descriptions": [{"lang": "en", "value": "CAPEC-33 HTTP Request Smuggling"}]}, {"capecId": "CAPEC-105", "descriptions": [{"lang": "en", "value": "CAPEC-105 HTTP Request Splitting"}]}], "metrics": [{"cvssV4_0": {"attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "baseScore": 2.1, "baseSeverity": "LOW", "privilegesRequired": "NONE", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-93", "description": "CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-06-08T16:34:58.505Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-49756.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-49756"}, {"tags": ["patch"], "url": "https://github.com/wojtekmach/req/commit/74506ff2c5addf74df85d79dc726e9b2e264a8ba"}], "source": {"discovery": "EXTERNAL"}, "title": "Multipart form-data header injection in Req via unescaped name/filename/content_type", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Sanitize attacker-influenced <tt>name</tt>, <tt>filename</tt>, and <tt>content_type</tt> values before passing them to <tt>'Elixir.Req':post/2</tt> with <tt>form_multipart:</tt>. At minimum, reject (or strip) any value containing <tt>\\r</tt>, <tt>\\n</tt>, or <tt>\"</tt>. When forwarding uploads, derive <tt>filename</tt> from a normalised string rather than <tt>Path.basename/1</tt> on a user-controlled path.</p>"}], "value": "Sanitize attacker-influenced name, filename, and content_type values before passing them to Req.post/2 with form_multipart:. At minimum, reject (or strip) any value containing \\r, \\n, or \". When forwarding uploads, derive filename from a normalised string rather than Path.basename/1 on a user-controlled path."}], "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"references": [{"url": "https://github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-06-08T16:05:54.070488Z", "id": "CVE-2026-49756", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-08T16:05:58.580Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-49756", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-06-01T13:45:22.448Z", "datePublished": "2026-06-08T15:20:24.035Z", "dateUpdated": "2026-06-08T16:05:58.580Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Req.Utils'"], "packageName": "req", "packageURL": "pkg:hex/req", "product": "req", "programFiles": ["lib/req/utils.ex"], "programRoutines": [{"name": "'Elixir.Req.Utils':encode_form_part/2"}], "repo": "https://github.com/wojtekmach/req", "vendor": "wojtekmach", "versions": [{"lessThan": "0.6.0", "status": "affected", "version": "0.5.3", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Req.Utils'"], "packageName": "wojtekmach/req", "packageURL": "pkg:github/wojtekmach/req", "product": "req", "programFiles": ["lib/req/utils.ex"], "programRoutines": [{"name": "'Elixir.Req.Utils':encode_form_part/2"}], "repo": "https://github.com/wojtekmach/req.git", "vendor": "wojtekmach", "versions": [{"lessThan": "74506ff2c5addf74df85d79dc726e9b2e264a8ba", "status": "affected", "version": "60253dbe9436cb8e9c738f895032f2e87939b597", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*", "versionEndExcluding": "0.6.0", "versionStartIncluding": "0.5.3", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Wojtek Mach"}, {"lang": "en", "type": "analyst", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in wojtekmach Req allows multipart parameter smuggling via attacker-influenced part metadata.<p><tt>'Elixir.Req.Utils':encode_form_part/2</tt> in <tt>lib/req/utils.ex</tt> builds the per-part headers by interpolating the caller-supplied <tt>name</tt>, <tt>filename</tt>, and <tt>content_type</tt> values directly into the <tt>content-disposition</tt> and <tt>content-type</tt> lines with no escaping or CRLF stripping. 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Any application that forwards user-controlled filenames (or field names / MIME types) through <tt>'Elixir.Req':post/2</tt> with <tt>form_multipart:</tt> lets an attacker inject arbitrary headers into the outgoing multipart body or smuggle additional fields and parts into the request the victim service sends downstream.</p><p>This issue affects req: from 0.5.3 before 0.6.0.</p>"}], "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in wojtekmach Req allows multipart parameter smuggling via attacker-influenced part metadata.\n\nReq.Utils.encode_form_part/2 in lib/req/utils.ex builds the per-part headers by interpolating the caller-supplied name, filename, and content_type values directly into the content-disposition and content-type lines with no escaping or CRLF stripping. A value containing \", \\r, or \\n closes the surrounding quoted value and starts a new header line; an additional \\r\\n--<boundary> terminates the current part and prepends a smuggled part of the attacker's choosing.\n\nThis is reachable through every supported way of supplying a part. It is particularly easy when value is a %File.Stream{}, because filename then defaults to Path.basename(stream.path) and POSIX filenames may legitimately contain \\r and \\n. Any application that forwards user-controlled filenames (or field names / MIME types) through Req.post/2 with form_multipart: lets an attacker inject arbitrary headers into the outgoing multipart body or smuggle additional fields and parts into the request the victim service sends downstream.\n\nThis issue affects req: from 0.5.3 before 0.6.0."}], "impacts": [{"capecId": "CAPEC-33", "descriptions": [{"lang": "en", "value": "CAPEC-33 HTTP Request Smuggling"}]}, {"capecId": "CAPEC-105", "descriptions": [{"lang": "en", "value": "CAPEC-105 HTTP Request Splitting"}]}], "metrics": [{"cvssV4_0": {"attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "baseScore": 2.1, "baseSeverity": "LOW", "privilegesRequired": "NONE", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-93", "description": "CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-06-08T15:20:24.035Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-49756.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-49756"}, {"tags": ["patch"], "url": "https://github.com/wojtekmach/req/commit/74506ff2c5addf74df85d79dc726e9b2e264a8ba"}], "source": {"discovery": "EXTERNAL"}, "title": "Multipart form-data header injection in Req via unescaped name/filename/content_type", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Sanitize attacker-influenced <tt>name</tt>, <tt>filename</tt>, and <tt>content_type</tt> values before passing them to <tt>'Elixir.Req':post/2</tt> with <tt>form_multipart:</tt>. At minimum, reject (or strip) any value containing <tt>\\r</tt>, <tt>\\n</tt>, or <tt>\"</tt>. When forwarding uploads, derive <tt>filename</tt> from a normalised string rather than <tt>Path.basename/1</tt> on a user-controlled path.</p>"}], "value": "Sanitize attacker-influenced name, filename, and content_type values before passing them to Req.post/2 with form_multipart:. At minimum, reject (or strip) any value containing \\r, \\n, or \". When forwarding uploads, derive filename from a normalised string rather than Path.basename/1 on a user-controlled path."}], "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-49756", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-08T16:05:54.070488Z"}}}], "references": [{"url": "https://github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-08T16:05:28.978Z"}}]}}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in wojtekmach Req allows multipart parameter smuggling via attacker-influenced part metadata.\n\nReq.Utils.encode_form_part/2 in lib/req/utils.ex builds the per-part headers by interpolating the caller-supplied name, filename, and content_type values directly into the content-disposition and content-type lines with no escaping or CRLF stripping. A value containing \", \\r, or \\n closes the surrounding quoted value and starts a new header line; an additional \\r\\n--<boundary> terminates the current part and prepends a smuggled part of the attacker's choosing.\n\nThis is reachable through every supported way of supplying a part. It is particularly easy when value is a %File.Stream{}, because filename then defaults to Path.basename(stream.path) and POSIX filenames may legitimately contain \\r and \\n. Any application that forwards user-controlled filenames (or field names / MIME types) through Req.post/2 with form_multipart: lets an attacker inject arbitrary headers into the outgoing multipart body or smuggle additional fields and parts into the request the victim service sends downstream.\n\nThis issue affects req: from 0.5.3 before 0.6.0."}], "id": "CVE-2026-49756", "lastModified": "2026-06-08T16:16:44.040", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 2.1, "baseSeverity": "LOW", "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": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-06-08T16:16:44.040", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-49756.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/wojtekmach/req/commit/74506ff2c5addf74df85d79dc726e9b2e264a8ba"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-49756"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-93"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

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