{"id":"CURL-CVE-2026-86414","summary":"leaking host credentials to HTTP proxy","details":"An HTTP proxy can trick libcurl into sending the origin's credentials (Basic\npassword, or a Negotiate/Kerberos ticket) to the proxy itself, by answering\nthe `CONNECT` tunnel request with 401 `WWW-Authenticate:` instead of the\nexpected 407 `Proxy-Authenticate:`.","aliases":["CVE-2026-86414"],"modified":"2026-10-14T07:04:27.047238565Z","published":"2026-10-14T08:00:00Z","database_specific":{"URL":"https://curl.se/docs/CVE-2026-86414.json","www":"https://curl.se/docs/CVE-2026-86414.html","issue":"https://hackerone.com/reports/3993566","CWE":{"id":"CWE-201","desc":"Information Exposure Through Sent Data"},"last_affected":"8.22.0","severity":"Low","package":"curl","affects":"both"},"affected":[{"ranges":[{"type":"SEMVER","events":[{"introduced":"7.10.8"},{"fixed":"8.23.0"}]},{"type":"GIT","repo":"https://github.com/curl/curl.git","events":[{"introduced":"52ceab5e41a01b4d1227876d51a3680a3ce5a841"},{"fixed":"2956af6c7451029fb12c12f8166dff211f930d52"}]}],"versions":["8.22.0","8.21.0","8.20.0","8.19.0","8.18.0","8.17.0","8.16.0","8.15.0","8.14.1","8.14.0","8.13.0","8.12.1","8.12.0","8.11.1","8.11.0","8.10.1","8.10.0","8.9.1","8.9.0","8.8.0","8.7.1","8.7.0","8.6.0","8.5.0","8.4.0","8.3.0","8.2.1","8.2.0","8.1.2","8.1.1","8.1.0","8.0.1","8.0.0","7.88.1","7.88.0","7.87.0","7.86.0","7.85.0","7.84.0","7.83.1","7.83.0","7.82.0","7.81.0","7.80.0","7.79.1","7.79.0","7.78.0","7.77.0","7.76.1","7.76.0","7.75.0","7.74.0","7.73.0","7.72.0","7.71.1","7.71.0","7.70.0","7.69.1","7.69.0","7.68.0","7.67.0","7.66.0","7.65.3","7.65.2","7.65.1","7.65.0","7.64.1","7.64.0","7.63.0","7.62.0","7.61.1","7.61.0","7.60.0","7.59.0","7.58.0","7.57.0","7.56.1","7.56.0","7.55.1","7.55.0","7.54.1","7.54.0","7.53.1","7.53.0","7.52.1","7.52.0","7.51.0","7.50.3","7.50.2","7.50.1","7.50.0","7.49.1","7.49.0","7.48.0","7.47.1","7.47.0","7.46.0","7.45.0","7.44.0","7.43.0","7.42.1","7.42.0","7.41.0","7.40.0","7.39.0","7.38.0","7.37.1","7.37.0","7.36.0","7.35.0","7.34.0","7.33.0","7.32.0","7.31.0","7.30.0","7.29.0","7.28.1","7.28.0","7.27.0","7.26.0","7.25.0","7.24.0","7.23.1","7.23.0","7.22.0","7.21.7","7.21.6","7.21.5","7.21.4","7.21.3","7.21.2","7.21.1","7.21.0","7.20.1","7.20.0","7.19.7","7.19.6","7.19.5","7.19.4","7.19.3","7.19.2","7.19.1","7.19.0","7.18.2","7.18.1","7.18.0","7.17.1","7.17.0","7.16.4","7.16.3","7.16.2","7.16.1","7.16.0","7.15.5","7.15.4","7.15.3","7.15.2","7.15.1","7.15.0","7.14.1","7.14.0","7.13.2","7.13.1","7.13.0","7.12.3","7.12.2","7.12.1","7.12.0","7.11.2","7.11.1","7.11.0","7.10.8","curl-8_22_0","rc-8_22_0-3","rc-8_22_0-2","rc-8_22_0-1","curl-8_21_0","rc-8_21_0-3","rc-8_21_0-2","rc-8_21_0-1","curl-8_20_0","rc-8_20_0-3","rc-8_20_0-2","rc-8_20_0-1","curl-8_19_0","rc-8_19_0-3","rc-8_19_0-2","rc-8_19_0-1","curl-8_18_0","rc-8_18_0-3","rc-8_18_0-2","rc-8_18_0-1","curl-8_17_0","curl-8_16_0","curl-8_15_0","curl-8_14_1","curl-8_14_0","curl-8_13_0","curl-8_12_1","curl-8_12_0","curl-8_11_1","curl-8_11_0","curl-8_10_1","curl-8_10_0","curl-8_9_1","curl-8_9_0","curl-8_8_0","curl-8_7_1","curl-8_7_0","curl-8_6_0","curl-8_5_0","tiny-curl-8_4_0","curl-8_4_0","curl-8_3_0","curl-8_2_1","curl-8_2_0","curl-8_1_2","curl-8_1_1","curl-8_1_0","curl-8_0_1","curl-8_0_0","curl-7_88_1","curl-7_88_0","curl-7_87_0","curl-7_86_0","curl-7_85_0","curl-7_84_0","curl-7_83_1","curl-7_83_0","curl-7_82_0","curl-7_81_0","curl-7_80_0","curl-7_79_1","curl-7_79_0","curl-7_78_0","curl-7_77_0","curl-7_76_1","curl-7_76_0","curl-7_75_0","curl-7_74_0","curl-7_73_0","tiny-curl-7_72_0","curl-7_72_0","curl-7_71_1","curl-7_71_0","curl-7_70_0","curl-7_69_1","curl-7_69_0","curl-7_68_0","curl-7_67_0","curl-7_66_0","curl-7_65_3","curl-7_65_2","curl-7_65_1","curl-7_65_0","curl-7_64_1","curl-7_64_0","curl-7_63_0","curl-7_62_0","curl-7_61_1","curl-7_61_0","curl-7_60_0","curl-7_59_0","curl-7_58_0","curl-7_57_0","curl-7_56_1","curl-7_56_0","curl-7_55_1","curl-7_55_0","curl-7_54_1","curl-7_54_0","curl-7_53_1","curl-7_53_0","curl-7_52_1","curl-7_52_0","curl-7_51_0","curl-7_50_3","curl-7_50_2","curl-7_50_1","curl-7_50_0","curl-7_49_1","curl-7_49_0","curl-7_48_0","curl-7_47_1","curl-7_47_0","curl-7_46_0","curl-7_45_0","curl-7_44_0","curl-7_43_0","curl-7_42_1","curl-7_42_0","curl-7_41_0","curl-7_40_0","curl-7_39_0","curl-7_38_0","curl-7_37_1","curl-7_37_0","curl-7_36_0","curl-7_35_0","curl-7_34_0","curl-7_33_0","curl-7_32_0","curl-7_31_0","curl-7_30_0","curl-7_29_0","curl-7_28_1","curl-7_28_0","curl-7_27_0","curl-7_26_0","curl-7_25_0","curl-7_24_0","curl-7_23_1","curl-7_23_0","curl-7_22_0","curl-7_21_7","curl-7_21_6","curl-7_21_5","curl-7_21_4","curl-7_21_3","curl-7_21_2","curl-7_21_1","curl-7_21_0","curl-7_20_1","curl-7_20_0","curl-7_19_7","curl-7_19_6","curl-7_19_5","curl-7_19_4","curl-7_19_3","curl-7_19_2","curl-7_19_1","curl-7_19_0","curl-7_18_2","curl-7_18_1","curl-7_18_0","curl-7_17_1","curl-7_17_0","curl-7_17_0-preldapfix","curl-7_16_4","curl-7_16_3","curl-7_16_2","curl-7_16_1","curl-7_16_0","curl-7_15_6-prepipeline","curl-7_15_5","curl-7_15_4","curl-7_15_3","curl-7_15_2","curl-7_15_1","curl-7_15_0","curl-7_14_1","curl-7_14_0","curl-7_13_2","curl-7_13_1","before_ftp_statemachine","curl-7_13_0","curl-7_12_3","curl-7_12_2","curl-7_12_1","curl-7_12_0","curl-7_11_2","curl-7_11_1","curl-7_11_0","curl-7_10_8"],"database_specific":{"vanir_signatures":[{"target":{"function":"on_resp_header","file":"lib/cf-h1-proxy.c"},"deprecated":false,"digest":{"length":2081,"function_hash":"257637578855016841248657910277963897518"},"id":"CURL-CVE-2026-86414-7cce8e09","signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/2956af6c7451029fb12c12f8166dff211f930d52"},{"deprecated":false,"digest":{"line_hashes":["312160267926895481502484276438322824177","81200633714028850629145386112541521810","307129665221017983598257068056937627788","45164055031776551579620442550624133895","251900367188319030478777019251472565532","328601495639528051212027628404064657758","78392878748253805392452861055293441470"],"threshold":0.9},"id":"CURL-CVE-2026-86414-a17b75a6","signature_type":"Line","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/2956af6c7451029fb12c12f8166dff211f930d52","target":{"file":"lib/http_proxy.c"}},{"target":{"file":"lib/http_proxy.c","function":"Curl_http_proxy_inspect_tunnel_response"},"deprecated":false,"digest":{"function_hash":"269369611843920935469892527381525002327","length":2363},"id":"CURL-CVE-2026-86414-aa4b6a29","signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/2956af6c7451029fb12c12f8166dff211f930d52"},{"source":"https://github.com/curl/curl.git/commit/2956af6c7451029fb12c12f8166dff211f930d52","target":{"file":"lib/cf-h1-proxy.c"},"deprecated":false,"digest":{"line_hashes":["329741433017589350415903422681748816887","253931529352840928795594931366939155610","89298656464641518414510640319763913616","93922929159459781266061183298742719755","305950444821924365518518222990579113729","296342007717287381101619484603129453125","199619961690389856653630266045228532095","84498895813186930599298433467646894197","93922929159459781266061183298742719755","305950444821924365518518222990579113729"],"threshold":0.9},"id":"CURL-CVE-2026-86414-f5580e9e","signature_type":"Line","signature_version":"v1"},{"signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/2956af6c7451029fb12c12f8166dff211f930d52","target":{"file":"lib/cf-h1-proxy.c","function":"on_resp_header_udp"},"deprecated":false,"digest":{"function_hash":"249128068805780593915379615774863356564","length":2648},"id":"CURL-CVE-2026-86414-faabc579"}],"vanir_signatures_modified":"2026-10-14T07:04:27Z","source":"https://curl.se/docs/CURL-CVE-2026-86414.json"}}],"schema_version":"1.9.0","credits":[{"name":"Stanislav Fort (Aisle Research)","type":"FINDER"},{"name":"Stefan Eissing","type":"REMEDIATION_DEVELOPER"}]}