{"api_version":"1","generated_at":"2026-08-28T03:52:32+00:00","cve":"CVE-2026-77341","urls":{"html":"https://cve.report/CVE-2026-77341","api":"https://cve.report/api/cve/CVE-2026-77341.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-77341","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77341"},"summary":{"title":"cpp-httplib: CRLF injection via unvalidated HTTP trailer headers in chunked response writing","description":"cpp-httplib is a C++ header-only HTTP/HTTPS library. In version 0.49.0, the chunked-response trailer output path writes trailer header names and values directly to the socket without validating them, allowing CRLF sequences in a trailer field to inject additional headers or split the HTTP response. Unlike every other header-writing path in the library, the trailer-writing code applies none of the field-name and field-value checks that reject carriage return and line feed, so an application that places attacker-influenced data into a chunked response trailer emits attacker-controlled CRLF onto the wire. This enables HTTP response splitting, letting an attacker forge response headers or inject a second response. This issue is fixed in version 0.50.0.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-08-28 00:18:15","updated_at":"2026-08-28 00:18:15"},"problem_types":["CWE-93","CWE-113","CWE-93 CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","CWE-113 CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')"],"metrics":[{"version":"4.0","source":"security-advisories@github.com","type":"Secondary","score":"5.3","severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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","data":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","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":"DECLARED","score":"5.3","severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","data":{"attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"PASSIVE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW"}}],"references":[{"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c","name":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/yhirose/cpp-httplib/commit/568d434e72fc51729d0ad33abffb181e5f7a453d","name":"https://github.com/yhirose/cpp-httplib/commit/568d434e72fc51729d0ad33abffb181e5f7a453d","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-77341","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77341","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"yhirose","product":"cpp-httplib","version":"affected >= 0.49.0, < 0.50.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"cpp-httplib","vendor":"yhirose","versions":[{"status":"affected","version":">= 0.49.0, < 0.50.0"}]}],"descriptions":[{"lang":"en","value":"cpp-httplib is a C++ header-only HTTP/HTTPS library. In version 0.49.0, the chunked-response trailer output path writes trailer header names and values directly to the socket without validating them, allowing CRLF sequences in a trailer field to inject additional headers or split the HTTP response. Unlike every other header-writing path in the library, the trailer-writing code applies none of the field-name and field-value checks that reject carriage return and line feed, so an application that places attacker-influenced data into a chunked response trailer emits attacker-controlled CRLF onto the wire. This enables HTTP response splitting, letting an attacker forge response headers or inject a second response. This issue is fixed in version 0.50.0."}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"PASSIVE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-93","description":"CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-113","description":"CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-27T22:16:45.356Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c","tags":["x_refsource_CONFIRM"],"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c"},{"name":"https://github.com/yhirose/cpp-httplib/commit/568d434e72fc51729d0ad33abffb181e5f7a453d","tags":["x_refsource_MISC"],"url":"https://github.com/yhirose/cpp-httplib/commit/568d434e72fc51729d0ad33abffb181e5f7a453d"}],"source":{"advisory":"GHSA-2r2h-jc8w-w66c","discovery":"UNKNOWN"},"title":"cpp-httplib: CRLF injection via unvalidated HTTP trailer headers in chunked response writing"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-77341","datePublished":"2026-08-27T22:16:45.356Z","dateReserved":"2026-08-20T19:28:35.243Z","dateUpdated":"2026-08-27T22:16:45.356Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-28 00:18:15","lastModifiedDate":"2026-08-28 00:18:15","problem_types":["CWE-93","CWE-113","CWE-93 CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","CWE-113 CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')"],"metrics":{"cvssMetricV40":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","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"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"77341","Ordinal":"1","Title":"cpp-httplib: CRLF injection via unvalidated HTTP trailer headers","CVE":"CVE-2026-77341","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"77341","Ordinal":"1","NoteData":"cpp-httplib is a C++ header-only HTTP/HTTPS library. In version 0.49.0, the chunked-response trailer output path writes trailer header names and values directly to the socket without validating them, allowing CRLF sequences in a trailer field to inject additional headers or split the HTTP response. Unlike every other header-writing path in the library, the trailer-writing code applies none of the field-name and field-value checks that reject carriage return and line feed, so an application that places attacker-influenced data into a chunked response trailer emits attacker-controlled CRLF onto the wire. This enables HTTP response splitting, letting an attacker forge response headers or inject a second response. This issue is fixed in version 0.50.0.","Type":"Description","Title":"cpp-httplib: CRLF injection via unvalidated HTTP trailer headers"}]}}}