{"id":"CURL-CVE-2026-82209","summary":"domain-scoped PSL domain cookie","details":"When libpsl support is enabled, libcurl fails to enforce the Public Suffix\nList boundary check when processing a `Set-Cookie` header where the `Domain`\nattribute explicitly matches an origin host that is itself a public suffix\n(e.g., `Domain=co.uk` set by `co.uk`).\n\nInstead of coercing it into a strict host-only cookie, libcurl saves the\ncookie with wildcard domain scope (`.co.uk`). Consequently, the cookie is\ninappropriately included in subsequent outbound requests or HTTP redirects to\narbitrary sibling subdomains under the same public suffix (e.g.,\n`attacker.co.uk`).","aliases":["CVE-2026-82209"],"modified":"2026-09-02T08:04:19.510649Z","published":"2026-09-02T08:00:00Z","database_specific":{"severity":"Low","www":"https://curl.se/docs/CVE-2026-82209.html","CWE":{"id":"CWE-201","desc":"Information Exposure Through Sent Data"},"URL":"https://curl.se/docs/CVE-2026-82209.json","affects":"both","issue":"https://hackerone.com/reports/3972385","last_affected":"8.21.0","package":"curl"},"affected":[{"ranges":[{"type":"SEMVER","events":[{"introduced":"7.46.0"},{"fixed":"8.22.0"}]},{"type":"GIT","repo":"https://github.com/curl/curl.git","events":[{"introduced":"e77b5b7453c1e8ccd7ec0816890d98e2f392e465"},{"fixed":"95c1e8915dce64606bd753fd47fc0bd236e31cd6"}]}],"versions":["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","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"],"database_specific":{"vanir_signatures":[{"target":{"file":"lib/cookie.c","function":"is_public_suffix"},"deprecated":false,"digest":{"function_hash":"213908973564268594638752847231949979873","length":1541},"id":"CURL-CVE-2026-82209-2d294af4","signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/95c1e8915dce64606bd753fd47fc0bd236e31cd6"},{"signature_type":"Function","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/95c1e8915dce64606bd753fd47fc0bd236e31cd6","target":{"file":"lib/cookie.c","function":"Curl_cookie_add"},"deprecated":false,"digest":{"function_hash":"222278781498688503787787149637841757802","length":1968},"id":"CURL-CVE-2026-82209-3e6d2661"},{"id":"CURL-CVE-2026-82209-9c5731a5","signature_type":"Line","signature_version":"v1","source":"https://github.com/curl/curl.git/commit/95c1e8915dce64606bd753fd47fc0bd236e31cd6","target":{"file":"lib/cookie.c"},"deprecated":false,"digest":{"line_hashes":["21731868551911990400354518369227389333","311339764407599575675744290038700683018","67409538252246842468129996238415507633","224238131650987331527718603641182882494","51712989053120701785138910181342785258","62922986269795145090752633040670570483","92544284258673586415963021062531968348","14590852356148094742011252700767634914","240366736704082154951189601671281888744","102088696126812935081930637958153298509","3097192871563462358128540996551017003","292141583597009942329457207525873703953","145216581391913082276329618955851914563","116388533793503780493851995865121599403","53608696260299754480294834383817733622","276767620444654246698632291886791423708"],"threshold":0.9}}],"source":"https://curl.se/docs/CURL-CVE-2026-82209.json","vanir_signatures_modified":"2026-09-02T08:04:19Z"}}],"schema_version":"1.9.0","credits":[{"name":"Stanislav Fort (Aisle Research)","type":"FINDER"},{"name":"Daniel Stenberg","type":"REMEDIATION_DEVELOPER"}]}