{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-75484", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-08-18T10:30:01.764Z", "datePublished": "2026-08-20T21:11:27.523Z", "dateUpdated": "2026-08-20T21:11:27.523Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Bandit.HTTP2.Stream'"], "packageName": "bandit", "packageURL": "pkg:hex/bandit", "product": "bandit", "programFiles": ["lib/bandit/http2/stream.ex"], "programRoutines": [{"name": "'Elixir.Bandit.HTTP2.Stream':read_headers/1"}], "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [{"lessThan": "1.12.5", "status": "affected", "version": "1.4.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Bandit.HTTP2.Stream'"], "packageName": "mtrudel/bandit", "packageURL": "pkg:github/mtrudel/bandit", "product": "bandit", "programFiles": ["lib/bandit/http2/stream.ex"], "programRoutines": [{"name": "'Elixir.Bandit.HTTP2.Stream':read_headers/1"}], "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [{"lessThan": "d38cf046c9a3cae4d0f88001c2ceb4143f86366b", "status": "affected", "version": "fff06efe3be962b484bd4d3eb339372fda5a231f", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.12.5", "versionStartIncluding": "1.4.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "remediation developer", "value": "Mat Trudel"}, {"lang": "en", "type": "coordinator", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in mtrudel bandit allows an unauthenticated remote attacker to smuggle CR, LF, or NUL characters into application-visible request headers via HTTP/2. <code>Bandit.HTTP2.Stream.read_headers/1</code> validates pseudo-header placement and uniqueness, header-name casing, connection-specific headers, the <code>te</code> value, and <code>content-length</code>, but never checks field <em>values</em>. Because HPACK carries arbitrary octets, a HEADERS block whose field values contain <code>\\r</code>, <code>\\n</code>, or <code>\\0</code> decodes without error and the values land in <code>conn.req_headers</code> unchanged. The HTTP/1 path already rejects the same octets; HTTP/2 did not.</p>\n<p>Bandit itself is not a sink for the injected bytes: its own logging uses fixed strings or <code>inspect</code>, and HTTP/2 response headers are HPACK-encoded and separately rejected by Plug's <code>put_resp_header</code>, so response splitting is not reachable through this path. The risk is entirely in how a downstream application consumes header values, such as appending one verbatim to a plain-text log or concatenating it into an upstream request. A related gap bundled in the same fix: only <code>:method</code>, <code>:scheme</code>, and <code>:path</code> were checked for at most one occurrence; a duplicate <code>:authority</code> pseudo-header was accepted, with the first instance silently winning as <code>conn.host</code> while a conflicting value remained visible to the application.</p>\n<p>This issue affects bandit: from 1.4.0 before 1.12.5.</p>"}, {"base64": false, "type": "text/markdown", "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in mtrudel bandit allows an unauthenticated remote attacker to smuggle CR, LF, or NUL characters into application-visible request headers via HTTP/2. `Bandit.HTTP2.Stream.read_headers/1` validates pseudo-header placement and uniqueness, header-name casing, connection-specific headers, the `te` value, and `content-length`, but never checks field *values*. Because HPACK carries arbitrary octets, a HEADERS block whose field values contain `\\r`, `\\n`, or `\\0` decodes without error and the values land in `conn.req_headers` unchanged. The HTTP/1 path already rejects the same octets; HTTP/2 did not.\n\nBandit itself is not a sink for the injected bytes: its own logging uses fixed strings or `inspect`, and HTTP/2 response headers are HPACK-encoded and separately rejected by Plug's `put_resp_header`, so response splitting is not reachable through this path. The risk is entirely in how a downstream application consumes header values, such as appending one verbatim to a plain-text log or concatenating it into an upstream request. A related gap bundled in the same fix: only `:method`, `:scheme`, and `:path` were checked for at most one occurrence; a duplicate `:authority` pseudo-header was accepted, with the first instance silently winning as `conn.host` while a conflicting value remained visible to the application.\n\nThis issue affects bandit: from 1.4.0 before 1.12.5."}], "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in mtrudel bandit allows an unauthenticated remote attacker to smuggle CR, LF, or NUL characters into application-visible request headers via HTTP/2. Bandit.HTTP2.Stream.read_headers/1 validates pseudo-header placement and uniqueness, header-name casing, connection-specific headers, the te value, and content-length, but never checks field values. Because HPACK carries arbitrary octets, a HEADERS block whose field values contain \\r, \\n, or \\0 decodes without error and the values land in conn.req_headers unchanged. The HTTP/1 path already rejects the same octets; HTTP/2 did not.\n\nBandit itself is not a sink for the injected bytes: its own logging uses fixed strings or inspect, and HTTP/2 response headers are HPACK-encoded and separately rejected by Plug's put_resp_header, so response splitting is not reachable through this path. The risk is entirely in how a downstream application consumes header values, such as appending one verbatim to a plain-text log or concatenating it into an upstream request. A related gap bundled in the same fix: only :method, :scheme, and :path were checked for at most one occurrence; a duplicate :authority pseudo-header was accepted, with the first instance silently winning as conn.host while a conflicting value remained visible to the application.\n\nThis issue affects bandit: from 1.4.0 before 1.12.5."}], "impacts": [{"capecId": "CAPEC-81", "descriptions": [{"lang": "en", "value": "CAPEC-81 Web Server Logs Tampering"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 6.9, "baseSeverity": "MEDIUM", "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:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "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": "2026-08-20T21:11:27.523Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/mtrudel/bandit/security/advisories/GHSA-x3gh-xhj4-3vq8"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-75484.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-75484"}, {"tags": ["patch"], "url": "https://github.com/mtrudel/bandit/commit/d38cf046c9a3cae4d0f88001c2ceb4143f86366b"}], "source": {"discovery": "UNKNOWN"}, "title": "HTTP/2 header field values containing CR, LF or NUL are passed to the application unvalidated in Bandit"}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Bandit.HTTP2.Stream'"], "packageName": "bandit", "packageURL": "pkg:hex/bandit", "product": "bandit", "programFiles": ["lib/bandit/http2/stream.ex"], "programRoutines": [{"name": "'Elixir.Bandit.HTTP2.Stream':read_headers/1"}], "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [{"lessThan": "1.12.5", "status": "affected", "version": "1.4.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.Bandit.HTTP2.Stream'"], "packageName": "mtrudel/bandit", "packageURL": "pkg:github/mtrudel/bandit", "product": "bandit", "programFiles": ["lib/bandit/http2/stream.ex"], "programRoutines": [{"name": "'Elixir.Bandit.HTTP2.Stream':read_headers/1"}], "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [{"lessThan": "d38cf046c9a3cae4d0f88001c2ceb4143f86366b", "status": "affected", "version": "fff06efe3be962b484bd4d3eb339372fda5a231f", "versionType": "git"}]}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in mtrudel bandit allows an unauthenticated remote attacker to smuggle CR, LF, or NUL characters into application-visible request headers via HTTP/2. Bandit.HTTP2.Stream.read_headers/1 validates pseudo-header placement and uniqueness, header-name casing, connection-specific headers, the te value, and content-length, but never checks field values. Because HPACK carries arbitrary octets, a HEADERS block whose field values contain \\r, \\n, or \\0 decodes without error and the values land in conn.req_headers unchanged. The HTTP/1 path already rejects the same octets; HTTP/2 did not.\n\nBandit itself is not a sink for the injected bytes: its own logging uses fixed strings or inspect, and HTTP/2 response headers are HPACK-encoded and separately rejected by Plug's put_resp_header, so response splitting is not reachable through this path. The risk is entirely in how a downstream application consumes header values, such as appending one verbatim to a plain-text log or concatenating it into an upstream request. A related gap bundled in the same fix: only :method, :scheme, and :path were checked for at most one occurrence; a duplicate :authority pseudo-header was accepted, with the first instance silently winning as conn.host while a conflicting value remained visible to the application.\n\nThis issue affects bandit: from 1.4.0 before 1.12.5."}], "id": "CVE-2026-75484", "lastModified": "2026-08-20T21:17:09.597", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "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:N/PR:N/UI:N/VC:N/VI:L/VA:N/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": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-08-20T21:17:09.597", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-75484.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/mtrudel/bandit/commit/d38cf046c9a3cae4d0f88001c2ceb4143f86366b"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/mtrudel/bandit/security/advisories/GHSA-x3gh-xhj4-3vq8"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-75484"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-93"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

{}

{}