{"id":"CVE-2026-6276","summary":"stale custom cookie host causes cookie leak","details":"Using libcurl, when a custom `Host:` header is first set for an HTTP request\nand a second request is subsequently done using the same *easy handle* but\nwithout the custom `Host:` header set, the second request would use stale\ninformation and pass on cookies meant for the first host in the second\nrequest. Leak them.","aliases":["CURL-CVE-2026-6276"],"modified":"2026-07-08T08:12:41.217272564Z","published":"2026-05-13T08:28:19.273Z","related":["SUSE-SU-2026:1717-1","SUSE-SU-2026:1940-1","SUSE-SU-2026:21452-1","SUSE-SU-2026:22146-1","SUSE-SU-2026:22156-1","SUSE-SU-2026:2703-1","openSUSE-SU-2026:10674-1","openSUSE-SU-2026:20973-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6276.json","cna_assigner":"curl","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"8.19.0"},{"last_affected":"8.19.0"},{"introduced":"8.18.0"},{"last_affected":"8.18.0"},{"introduced":"8.17.0"},{"last_affected":"8.17.0"},{"introduced":"8.16.0"},{"last_affected":"8.16.0"},{"introduced":"8.15.0"},{"last_affected":"8.15.0"},{"introduced":"8.14.1"},{"last_affected":"8.14.1"},{"introduced":"8.14.0"},{"last_affected":"8.14.0"},{"introduced":"8.13.0"},{"last_affected":"8.13.0"},{"introduced":"8.12.1"},{"last_affected":"8.12.1"},{"introduced":"8.12.0"},{"last_affected":"8.12.0"},{"introduced":"8.11.1"},{"last_affected":"8.11.1"},{"introduced":"8.11.0"},{"last_affected":"8.11.0"},{"introduced":"8.10.1"},{"last_affected":"8.10.1"},{"introduced":"8.10.0"},{"last_affected":"8.10.0"},{"introduced":"8.9.1"},{"last_affected":"8.9.1"},{"introduced":"8.9.0"},{"last_affected":"8.9.0"},{"introduced":"8.8.0"},{"last_affected":"8.8.0"},{"introduced":"8.7.1"},{"last_affected":"8.7.1"},{"introduced":"8.7.0"},{"last_affected":"8.7.0"},{"introduced":"8.6.0"},{"last_affected":"8.6.0"},{"introduced":"8.5.0"},{"last_affected":"8.5.0"},{"introduced":"8.4.0"},{"last_affected":"8.4.0"},{"introduced":"8.3.0"},{"last_affected":"8.3.0"},{"introduced":"8.2.1"},{"last_affected":"8.2.1"},{"introduced":"8.2.0"},{"last_affected":"8.2.0"},{"introduced":"8.1.2"},{"last_affected":"8.1.2"},{"introduced":"8.1.1"},{"last_affected":"8.1.1"},{"introduced":"8.1.0"},{"last_affected":"8.1.0"},{"introduced":"8.0.1"},{"last_affected":"8.0.1"},{"introduced":"8.0.0"},{"last_affected":"8.0.0"},{"introduced":"7.88.1"},{"last_affected":"7.88.1"},{"introduced":"7.88.0"},{"last_affected":"7.88.0"},{"introduced":"7.87.0"},{"last_affected":"7.87.0"},{"introduced":"7.86.0"},{"last_affected":"7.86.0"},{"introduced":"7.85.0"},{"last_affected":"7.85.0"},{"introduced":"7.84.0"},{"last_affected":"7.84.0"},{"introduced":"7.83.1"},{"last_affected":"7.83.1"},{"introduced":"7.83.0"},{"last_affected":"7.83.0"},{"introduced":"7.82.0"},{"last_affected":"7.82.0"},{"introduced":"7.81.0"},{"last_affected":"7.81.0"},{"introduced":"7.80.0"},{"last_affected":"7.80.0"},{"introduced":"7.79.1"},{"last_affected":"7.79.1"},{"introduced":"7.79.0"},{"last_affected":"7.79.0"},{"introduced":"7.78.0"},{"last_affected":"7.78.0"},{"introduced":"7.77.0"},{"last_affected":"7.77.0"},{"introduced":"7.76.1"},{"last_affected":"7.76.1"},{"introduced":"7.76.0"},{"last_affected":"7.76.0"},{"introduced":"7.75.0"},{"last_affected":"7.75.0"},{"introduced":"7.74.0"},{"last_affected":"7.74.0"},{"introduced":"7.73.0"},{"last_affected":"7.73.0"},{"introduced":"7.72.0"},{"last_affected":"7.72.0"},{"introduced":"7.71.1"},{"last_affected":"7.71.1"},{"introduced":"7.71.0"},{"last_affected":"7.71.0"}]}]},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/04/29/13"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-6276.html"},{"type":"WEB","url":"https://curl.se/docs/CVE-2026-6276.json"},{"type":"WEB","url":"https://hackerone.com/reports/3671818"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6276.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6276"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/curl/curl","events":[{"introduced":"e9db32a09af03f27e86d1251a9e68e9b7486d371"},{"fixed":"a05f34973e6c4bb629d018f7cb51487be1c904d8"}],"database_specific":{"source":"CPE_RANGE","extracted_events":[{"introduced":"7.71.0"},{"fixed":"8.20.0"}],"cpe":"cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*"}}],"versions":["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","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"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-202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