{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-114216", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-10-23T10:45:02.529Z", "datePublished": "2026-10-26T13:30:41.225Z", "dateUpdated": "2026-10-26T15:35:51.933Z" }, "containers": { "cna": { "affected": [ { "collectionURL": "https://repo.hex.pm", "cpes": [ "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "packageName": "bandit", "packageURL": "pkg:hex/bandit", "product": "bandit", "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [ { "lessThan": "1.14.0", "status": "affected", "version": "1.12.4", "versionType": "semver" } ] }, { "collectionURL": "https://github.com", "cpes": [ "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*" ], "defaultStatus": "unaffected", "packageName": "mtrudel/bandit", "packageURL": "pkg:github/mtrudel/bandit", "product": "bandit", "repo": "https://github.com/mtrudel/bandit", "vendor": "mtrudel", "versions": [ { "lessThan": "220b9dfd27f9a21305be2afc75cbe585ddc24e7a", "status": "affected", "version": "c31e9e3c76dcbfc239a96eabed5341ced7885ae5", "versionType": "git" } ] } ], "cpeApplicability": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.14.0", "versionStartIncluding": "1.12.4", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "AND" } ], "credits": [ { "lang": "en", "type": "reporter", "value": "Peter Ullrich" }, { "lang": "en", "type": "remediation developer", "value": "Mat Trudel" }, { "lang": "en", "type": "analyst", "value": "Jonatan Männchen / EEF" } ], "dateAssigned": "2026-10-23T12:59:00.000Z", "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end proxy via a chunk extension that contains a bare LF.

\n

The chunked reader in lib/bandit/http1/socket.ex takes the chunk-size line to be everything up to the first CRLF and discards everything after ; without checking it against the RFC 9112 chunk-ext grammar, so bare LF, bare CR and other control bytes pass. A proxy that ends the size line at a bare LF reads 2;\\nxx\\r\\n40\\r\\n... as one request whose second chunk holds a GET /admin, while Bandit ends the body early and dispatches GET /admin as a separate pipelined request. Deployments without such a proxy in front of Bandit are not affected.

\n

This issue affects bandit: from 1.12.4 before 1.14.0.

" }, { "base64": false, "type": "text/markdown", "value": "Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end proxy via a chunk extension that contains a bare LF.\n\nThe chunked reader in `lib/bandit/http1/socket.ex` takes the chunk-size line to be everything up to the first CRLF and discards everything after `;` without checking it against the RFC 9112 `chunk-ext` grammar, so bare LF, bare CR and other control bytes pass. A proxy that ends the size line at a bare LF reads `2;\\nxx\\r\\n40\\r\\n...` as one request whose second chunk holds a `GET /admin`, while Bandit ends the body early and dispatches `GET /admin` as a separate pipelined request. Deployments without such a proxy in front of Bandit are not affected.\n\nThis issue affects bandit: from 1.12.4 before 1.14.0." } ], "value": "Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end proxy via a chunk extension that contains a bare LF.\n\nThe chunked reader in lib/bandit/http1/socket.ex takes the chunk-size line to be everything up to the first CRLF and discards everything after ; without checking it against the RFC 9112 chunk-ext grammar, so bare LF, bare CR and other control bytes pass. A proxy that ends the size line at a bare LF reads 2;\\nxx\\r\\n40\\r\\n... as one request whose second chunk holds a GET /admin, while Bandit ends the body early and dispatches GET /admin as a separate pipelined request. Deployments without such a proxy in front of Bandit are not affected.\n\nThis issue affects bandit: from 1.12.4 before 1.14.0." } ], "impacts": [ { "capecId": "CAPEC-33", "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

Behind a front-end proxy that treats a bare LF as a line ending and forwards chunked bodies unchanged, an unauthenticated attacker can have Bandit run requests the proxy never saw, getting past the proxy's access controls.

" }, { "base64": false, "type": "text/markdown", "value": "Behind a front-end proxy that treats a bare LF as a line ending and forwards chunked bodies unchanged, an unauthenticated attacker can have Bandit run requests the proxy never saw, getting past the proxy's access controls." } ], "value": "Behind a front-end proxy that treats a bare LF as a line ending and forwards chunked bodies unchanged, an unauthenticated attacker can have Bandit run requests the proxy never saw, getting past the proxy's access controls." } ] } ], "metrics": [ { "cvssV4_0": { "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 6.3, "baseSeverity": "MEDIUM", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/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", "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": { "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-10-26T13:30:41.225Z" }, "references": [ { "name": "Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit", "tags": [ "vendor-advisory", "related" ], "url": "https://github.com/mtrudel/bandit/security/advisories/GHSA-w5wc-g2hc-g7m2" }, { "name": "EEF CNA record for CVE-2026-114216", "tags": [ "related" ], "url": "https://cna.erlef.org/cves/CVE-2026-114216.html" }, { "name": "OSV record EEF-CVE-2026-114216", "tags": [ "related" ], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-114216" }, { "name": "Introducing commit c31e9e3 in mtrudel/bandit", "tags": [ "related" ], "url": "https://github.com/mtrudel/bandit/commit/c31e9e3c76dcbfc239a96eabed5341ced7885ae5" }, { "name": "Fix commit 220b9df in mtrudel/bandit", "tags": [ "patch" ], "url": "https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a" } ], "source": { "discovery": "UNKNOWN" }, "title": "Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit", "workarounds": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

Where the front-end proxy can reach Bandit over HTTP/2, disable HTTP/1 with http_1_options: [enabled: false], so that the chunked body reader never runs.

" }, { "base64": false, "type": "text/markdown", "value": "Where the front-end proxy can reach Bandit over HTTP/2, disable HTTP/1 with `http_1_options: [enabled: false]`, so that the chunked body reader never runs." } ], "value": "Where the front-end proxy can reach Bandit over HTTP/2, disable HTTP/1 with http_1_options: [enabled: false], so that the chunked body reader never runs." } ], "x_proofOfConcept": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "
    \n
  1. Run Bandit with a Plug that reads the body and records each request's method and path.
    2. \n
  2. On one connection, send POST /public with Transfer-Encoding: chunked and the body 2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\n, followed directly by GET /admin HTTP/1.1 with Content-Length: 7 and the body \\r\\n0\\r\\n\\r\\n.
    3. \n
  3. Bandit dispatches both POST /public with the body 40 and GET /admin. A proxy that ends lines at a bare LF would have forwarded the same bytes as the single POST /public.
    4. \n
" }, { "base64": false, "type": "text/markdown", "value": "1. Run Bandit with a Plug that reads the body and records each request's method and path.\n2. On one connection, send `POST /public` with `Transfer-Encoding: chunked` and the body `2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\n`, followed directly by `GET /admin HTTP/1.1` with `Content-Length: 7` and the body `\\r\\n0\\r\\n\\r\\n`.\n3. Bandit dispatches both `POST /public` with the body `40` and `GET /admin`. A proxy that ends lines at a bare LF would have forwarded the same bytes as the single `POST /public`." } ], "value": "* Run Bandit with a Plug that reads the body and records each request's method and path.\n* On one connection, send POST /public with Transfer-Encoding: chunked and the body 2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\n, followed directly by GET /admin HTTP/1.1 with Content-Length: 7 and the body \\r\\n0\\r\\n\\r\\n.\n* Bandit dispatches both POST /public with the body 40 and GET /admin. A proxy that ends lines at a bare LF would have forwarded the same bytes as the single POST /public." } ], "x_technicalAnalysis": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

1. Unchecked extension. In lib/bandit/http1/socket.ex, the chunked body reader takes the chunk-size line to be everything up to the first CRLF. Anything after ; is thrown away without being checked against the RFC 9112 §7.1.1 chunk-ext grammar, so bare LF, bare CR and other control bytes are accepted. The 16-byte size-line cap does not help, because the payload needs only 5 bytes.

\n

2. Bandit's reading. For the body 2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\nGET /admin ..., Bandit takes 2;\\nxx as the size line and 40 as the 2-byte chunk, and the embedded 0\\r\\n\\r\\n ends the body. Bandit then runs GET /admin as a second pipelined request.

\n

3. The proxy's reading. A proxy that ends the size line at the bare LF sees only one POST, with the chunk xx and a 0x40-byte chunk that holds the GET /admin bytes.

" }, { "base64": false, "type": "text/markdown", "value": "**1. Unchecked extension.** In `lib/bandit/http1/socket.ex`, the chunked body reader takes the chunk-size line to be everything up to the first CRLF. Anything after `;` is thrown away without being checked against the RFC 9112 §7.1.1 `chunk-ext` grammar, so bare LF, bare CR and other control bytes are accepted. The 16-byte size-line cap does not help, because the payload needs only 5 bytes.\n\n**2. Bandit's reading.** For the body `2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\nGET /admin ...`, Bandit takes `2;\\nxx` as the size line and `40` as the 2-byte chunk, and the embedded `0\\r\\n\\r\\n` ends the body. Bandit then runs `GET /admin` as a second pipelined request.\n\n**3. The proxy's reading.** A proxy that ends the size line at the bare LF sees only one POST, with the chunk `xx` and a 0x40-byte chunk that holds the `GET /admin` bytes." } ], "value": "1. Unchecked extension. In lib/bandit/http1/socket.ex, the chunked body reader takes the chunk-size line to be everything up to the first CRLF. Anything after ; is thrown away without being checked against the RFC 9112 §7.1.1 chunk-ext grammar, so bare LF, bare CR and other control bytes are accepted. The 16-byte size-line cap does not help, because the payload needs only 5 bytes.\n\n2. Bandit's reading. For the body 2;\\nxx\\r\\n40\\r\\n0\\r\\n\\r\\nGET /admin ..., Bandit takes 2;\\nxx as the size line and 40 as the 2-byte chunk, and the embedded 0\\r\\n\\r\\n ends the body. Bandit then runs GET /admin as a second pipelined request.\n\n3. The proxy's reading. A proxy that ends the size line at the bare LF sees only one POST, with the chunk xx and a 0x40-byte chunk that holds the GET /admin bytes." } ] }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-114216", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-26T15:03:20.382433Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-26T15:35:51.933Z" } } ] } }