{"api_version":"1","generated_at":"2026-06-01T02:52:57+00:00","cve":"CVE-2026-45372","urls":{"html":"https://cve.report/CVE-2026-45372","api":"https://cve.report/api/cve/CVE-2026-45372.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-45372","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-45372"},"summary":{"title":"cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection","description":"cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \\r\\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-05-29 20:16:26","updated_at":"2026-05-29 20:23:08"},"problem_types":["CWE-93","CWE-444","CWE-93 CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","CWE-444 CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"9.9","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","baseScore":9.9,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"HIGH","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.9","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":9.9,"baseSeverity":"CRITICAL","confidentialityImpact":"LOW","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m","name":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45372","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45372","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"yhirose","product":"cpp-httplib","version":"affected < 0.44.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"45372","cve":"CVE-2026-45372","epss":"0.000410000","percentile":"0.129060000","score_date":"2026-05-31","updated_at":"2026-06-01 00:08:18"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"cpp-httplib","vendor":"yhirose","versions":[{"status":"affected","version":"< 0.44.0"}]}],"descriptions":[{"lang":"en","value":"cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \\r\\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":9.9,"baseSeverity":"CRITICAL","confidentialityImpact":"LOW","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-93","description":"CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-444","description":"CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-29T19:21:12.313Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m","tags":["x_refsource_CONFIRM"],"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m"}],"source":{"advisory":"GHSA-xjxg-64p4-vj4m","discovery":"UNKNOWN"},"title":"cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-45372","datePublished":"2026-05-29T19:21:12.313Z","dateReserved":"2026-05-12T00:51:29.086Z","dateUpdated":"2026-05-29T19:21:12.313Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-29 20:16:26","lastModifiedDate":"2026-05-29 20:23:08","problem_types":["CWE-93","CWE-444","CWE-93 CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","CWE-444 CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L","baseScore":9.9,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"HIGH","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":5.3}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"45372","Ordinal":"1","Title":"cpp-httplib: HTTP header value percent-decoding in server-side `","CVE":"CVE-2026-45372","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"45372","Ordinal":"1","NoteData":"cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \\r\\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.","Type":"Description","Title":"cpp-httplib: HTTP header value percent-decoding in server-side `"}]}}}