{"cve":"CVE-2026-82209","nvd":{"published":"2026-09-06T18:17:22.847","modified":"2026-09-15T07:16:31.233","status":"Modified","description":"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`).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N","score":8.2},"cwes":["CWE-201"],"references":["https://curl.se/docs/CVE-2026-82209.html","https://curl.se/docs/CVE-2026-82209.json","https://hackerone.com/reports/3972385","https://hackerone.com/reports/3972385"],"products":["haxx:curl"],"source":"nvd","synced_at":"2026-10-19T22:52:03.409947763+00:00"},"epss":{"cve":"CVE-2026-82209","score":0.00373,"percentile":0.31304,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}