{"id":"CVE-2026-6253","summary":"proxy credentials leak over redirect-to proxy","details":"curl might erroneously pass on credentials for a first proxy to a second\nproxy.\n\nThis can happen when the following conditions are true:\n\n1. curl is setup to use specific different proxies for different URL schemes\n2. the first proxy needs credentials\n3. the second proxy uses no credentials\n4. while using the first proxy (using say `http://`), curl is asked to follow\n   a redirect to a URL using another scheme (say `https://`), accessed using a\n   second, different, proxy","aliases":["CURL-CVE-2026-6253"],"modified":"2026-05-19T08:59:08.406503800Z","published":"2026-05-13T08:28:03.004Z","related":["SUSE-SU-2026:1717-1","SUSE-SU-2026:1940-1","SUSE-SU-2026:21452-1","openSUSE-SU-2026:10674-1"],"database_specific":{"cna_assigner":"curl","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"last_affected":"8.19.0"},{"last_affected":"8.18.0"},{"last_affected":"8.17.0"},{"last_affected":"8.16.0"},{"last_affected":"8.15.0"},{"last_affected":"8.14.1"},{"last_affected":"8.14.0"},{"last_affected":"8.13.0"},{"last_affected":"8.12.1"},{"last_affected":"8.12.0"},{"last_affected":"8.11.1"},{"last_affected":"8.11.0"},{"last_affected":"8.10.1"},{"last_affected":"8.10.0"},{"last_affected":"8.9.1"},{"last_affected":"8.9.0"},{"last_affected":"8.8.0"},{"last_affected":"8.7.1"},{"last_affected":"8.7.0"},{"last_affected":"8.6.0"},{"last_affected":"8.5.0"},{"last_affected":"8.4.0"},{"last_affected":"8.3.0"},{"last_affected":"8.2.1"},{"last_affected":"8.2.0"},{"last_affected":"8.1.2"},{"last_affected":"8.1.1"},{"last_affected":"8.1.0"},{"last_affected":"8.0.1"},{"last_affected":"8.0.0"},{"last_affected":"7.88.1"},{"last_affected":"7.88.0"},{"last_affected":"7.87.0"},{"last_affected":"7.86.0"},{"last_affected":"7.85.0"},{"last_affected":"7.84.0"},{"last_affected":"7.83.1"},{"last_affected":"7.83.0"},{"last_affected":"7.82.0"},{"last_affected":"7.81.0"},{"last_affected":"7.80.0"},{"last_affected":"7.79.1"},{"last_affected":"7.79.0"},{"last_affected":"7.78.0"},{"last_affected":"7.77.0"},{"last_affected":"7.76.1"},{"last_affected":"7.76.0"},{"last_affected":"7.75.0"},{"last_affected":"7.74.0"},{"last_affected":"7.73.0"},{"last_affected":"7.72.0"},{"last_affected":"7.71.1"},{"last_affected":"7.71.0"},{"last_affected":"7.70.0"},{"last_affected":"7.69.1"},{"last_affected":"7.69.0"},{"last_affected":"7.68.0"},{"last_affected":"7.67.0"},{"last_affected":"7.66.0"},{"last_affected":"7.65.3"},{"last_affected":"7.65.2"},{"last_affected":"7.65.1"},{"last_affected":"7.65.0"},{"last_affected":"7.64.1"},{"last_affected":"7.64.0"},{"last_affected":"7.63.0"},{"last_affected":"7.62.0"},{"last_affected":"7.61.1"},{"last_affected":"7.61.0"},{"last_affected":"7.60.0"},{"last_affected":"7.59.0"},{"last_affected":"7.58.0"},{"last_affected":"7.57.0"},{"last_affected":"7.56.1"},{"last_affected":"7.56.0"},{"last_affected":"7.55.1"},{"last_affected":"7.55.0"},{"last_affected":"7.54.1"},{"last_affected":"7.54.0"},{"last_affected":"7.53.1"},{"last_affected":"7.53.0"},{"last_affected":"7.52.1"},{"last_affected":"7.52.0"},{"last_affected":"7.51.0"},{"last_affected":"7.50.3"},{"last_affected":"7.50.2"},{"last_affected":"7.50.1"},{"last_affected":"7.50.0"},{"last_affected":"7.49.1"},{"last_affected":"7.49.0"},{"last_affected":"7.48.0"},{"last_affected":"7.47.1"},{"last_affected":"7.47.0"},{"last_affected":"7.46.0"},{"last_affected":"7.45.0"},{"last_affected":"7.44.0"},{"last_affected":"7.43.0"},{"last_affected":"7.42.1"},{"last_affected":"7.42.0"},{"last_affected":"7.41.0"},{"last_affected":"7.40.0"},{"last_affected":"7.39.0"},{"last_affected":"7.38.0"},{"last_affected":"7.37.1"},{"last_affected":"7.37.0"},{"last_affected":"7.36.0"},{"last_affected":"7.35.0"},{"last_affected":"7.34.0"},{"last_affected":"7.33.0"},{"last_affected":"7.32.0"},{"last_affected":"7.31.0"},{"last_affected":"7.30.0"},{"last_affected":"7.29.0"},{"last_affected":"7.28.1"},{"last_affected":"7.28.0"},{"last_affected":"7.27.0"},{"last_affected":"7.26.0"},{"last_affected":"7.25.0"},{"last_affected":"7.24.0"},{"last_affected":"7.23.1"},{"last_affected":"7.23.0"},{"last_affected":"7.22.0"},{"last_affected":"7.21.7"},{"last_affected":"7.21.6"},{"last_affected":"7.21.5"},{"last_affected":"7.21.4"},{"last_affected":"7.21.3"},{"last_affected":"7.21.2"},{"last_affected":"7.21.1"},{"last_affected":"7.21.0"},{"last_affected":"7.20.1"},{"last_affected":"7.20.0"},{"last_affected":"7.19.7"},{"last_affected":"7.19.6"},{"last_affected":"7.19.5"},{"last_affected":"7.19.4"},{"last_affected":"7.19.3"},{"last_affected":"7.19.2"},{"last_affected":"7.19.1"},{"last_affected":"7.19.0"},{"last_affected":"7.18.2"},{"last_affected":"7.18.1"},{"last_affected":"7.18.0"},{"last_affected":"7.17.1"},{"last_affected":"7.17.0"},{"last_affected":"7.16.4"},{"last_affected":"7.16.3"},{"last_affected":"7.16.2"},{"last_affected":"7.16.1"},{"last_affected":"7.16.0"},{"last_affected":"7.15.5"},{"last_affected":"7.15.4"},{"last_affected":"7.15.3"},{"last_affected":"7.15.2"},{"last_affected":"7.15.1"},{"last_affected":"7.15.0"},{"last_affected":"7.14.1"}]}],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6253.json"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/04/29/11"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-6253.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-6253.json"},{"type":"WEB","url":"https://hackerone.com/reports/3669637"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6253.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6253"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/curl/curl","events":[{"introduced":"6e1a986e0f35cf36618bd88f42e14ea856b6951b"},{"fixed":"a05f34973e6c4bb629d018f7cb51487be1c904d8"}],"database_specific":{"source":"CPE_FIELD","cpe":"cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"7.14.1"},{"fixed":"8.20.0"}]}}],"versions":["rc-8_20_0-3","rc-8_20_0-2","rc-8_20_0-1","curl-8_19_0","curl-8_18_0","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","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","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_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_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"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-6253.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}