{"id":"CVE-2025-46728","summary":"cpp-httplib has Unbounded Memory Allocation in Chunked/No-Length Requests","details":"cpp-httplib is a C++ header-only HTTP/HTTPS server and client library. Prior to version 0.20.1, the library fails to enforce configured size limits on incoming request bodies when `Transfer-Encoding: chunked` is used or when no `Content-Length` header is provided. A remote attacker can send a chunked request without the terminating zero-length chunk, causing uncontrolled memory allocation on the server. This leads to potential exhaustion of system memory and results in a server crash or unresponsiveness. Version 0.20.1 fixes the issue by enforcing limits during parsing. If the limit is exceeded at any point during reading, the connection is terminated immediately. A short-term workaround through a Reverse Proxy is available. If updating the library immediately is not feasible, deploy a reverse proxy (e.g., Nginx, HAProxy) in front of the `cpp-httplib` application. Configure the proxy to enforce maximum request body size limits, thereby stopping excessively large requests before they reach the vulnerable library code.","aliases":["GHSA-px83-72rx-v57c"],"modified":"2026-08-12T15:16:32.912814Z","published":"2025-05-06T00:45:25.130Z","related":["openSUSE-SU-2025:15084-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-400"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46728.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46728.json"},{"type":"ADVISORY","url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-px83-72rx-v57c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-46728"},{"type":"FIX","url":"https://github.com/yhirose/cpp-httplib/commit/7b752106ac42bd5b907793950d9125a0972c8e8e"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/yhirose/cpp-httplib","events":[{"introduced":"0"},{"fixed":"3af7f2c16147f3fbc6e4d717032daf505dc1652c"},{"fixed":"7b752106ac42bd5b907793950d9125a0972c8e8e"}],"database_specific":{"cpe":"cpe:2.3:a:cpp-httplib_project:cpp-httplib:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"0.20.1"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v0.20.0","v0.19.0","v0.18.7","v0.18.6","v0.18.5","v0.18.4","v0.18.3","v0.18.2","v0.18.1","v0.18.0","v0.17.3","v0.17.2","v0.17.1","v0.17.0","v0.16.3","v0.16.2","v0.16.1","v0.16.0","v0.15.3","v0.15.2","v0.15.1","v0.15.0","v0.14.3","v0.14.2","v0.14.1","v0.14.0","v0.13.3","v0.13.2","v0.13.1","v0.13.0","v0.12.6","v0.12.5","v0.12.4","v0.12.3","v0.12.2","v0.12.1","v0.12.0","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.11.0","v0.10.9","v0.10.8","v0.10.7","v0.10.6","v0.10.5","v0.10.4","v0.10.3","v0.10.2","v0.10.1","v0.10.0","v0.9.10","v0.9.9","v0.9.8","v0.9.7","v0.9.6","v0.9.5","v0.9.4","v0.9.3","v0.9.2","v0.9.1","v0.9.0","v0.8.9","v0.8.8","v0.8.7","v0.8.6","v0.8.5","v0.8.4","v0.8.3","v0.8.2","v0.8.1","v0.8.0","v0.7.18","v0.7.17","v0.7.16","v0.7.15","v0.7.14","v0.7.13","v0.7.12","v0.7.11","v0.7.10","v0.7.9","v0.7.8","v0.7.7","v0.7.6","v0.7.5","v0.7.4","v0.7.3","v0.7.2","v0.7.1","v0.7.0","v0.6.7","v0.6.6","v0.6.5","v0.6.4","v0.6.3","v0.6.2","v0.6.1","v0.6.0","v0.5.13","v0.5.12","v0.5.11","v0.5.10","v0.5.9","v0.5.8","v0.5.7","v0.5.6","v0.5.5","v0.5.4","v0.5.3","v0.5.2","v0.5.1","v0.5.0","v0.4.2","v0.4.1","v0.4.0","v0.3.3","v0.3.2","v0.3.1","v0.3.0","v0.2.6","v0.2.5","v0.2.4","v0.2.3","v0.2.2","v0.2.1","v0.2.0"],"database_specific":{"vanir_signatures_modified":"2026-08-12T15:16:32Z","vanir_signatures":[{"deprecated":false,"digest":{"function_hash":"273893763024305777493719782969948749593","length":568},"id":"CVE-2025-46728-18f6418d","signature_type":"Function","signature_version":"v1","source":"https://github.com/yhirose/cpp-httplib/commit/7b752106ac42bd5b907793950d9125a0972c8e8e","target":{"file":"httplib.h","function":"stream_line_reader::getline"}},{"source":"https://github.com/yhirose/cpp-httplib/commit/7b752106ac42bd5b907793950d9125a0972c8e8e","target":{"file":"test/test.cc"},"deprecated":false,"digest":{"line_hashes":["257985735793026435818868796645710254975","47152089635226046254886122597760746000","277935455136829786777737757595575415649","240428477853514944703987908155197738368","98734447240544736125538254896320203198","12401696439684324966363430957733437059","232918337349665503594913121985807921549","297344248686960807045559079316116779264","235855093667763522674929287323664717147","52669484370524566126415748220010415188"],"threshold":0.9},"id":"CVE-2025-46728-1b351755","signature_type":"Line","signature_version":"v1"},{"id":"CVE-2025-46728-d289d55f","signature_type":"Function","signature_version":"v1","source":"https://github.com/yhirose/cpp-httplib/commit/7b752106ac42bd5b907793950d9125a0972c8e8e","target":{"file":"test/test.cc","function":"SetUp"},"deprecated":false,"digest":{"function_hash":"88011015293096735173591467930571185687","length":19168}},{"id":"CVE-2025-46728-f50b3fbc","signature_type":"Line","signature_version":"v1","source":"https://github.com/yhirose/cpp-httplib/commit/7b752106ac42bd5b907793950d9125a0972c8e8e","target":{"file":"httplib.h"},"deprecated":false,"digest":{"line_hashes":["32898783120307941874368505242798629186","162037324753814312112070594927690416950","287480307527108457454058770006969193908","301745308707818391118521842106411970281","263861363138065655965234048318932182331","218911545314115535196603612996816985361","260379456301400884034826106084209849017"],"threshold":0.9}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-46728.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}