VULNERABILITY INTELLIGENCE

CVE-2026-82209

CVSS score8.2 HIGH
EPSS probability0.37%
CISA KEVNot currently listed
Published2026-09-06
Last modified2026-09-15
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

Description

When libpsl support is enabled, libcurl fails to enforce the Public Suffix List boundary check when processing a `Set-Cookie` header where the `Domain` attribute explicitly matches an origin host that is itself a public suffix (e.g., `Domain=co.uk` set by `co.uk`). Instead of coercing it into a strict host-only cookie, libcurl saves the cookie with wildcard domain scope (`.co.uk`). Consequently, the cookie is inappropriately included in subsequent outbound requests or HTTP redirects to arbitrary sibling subdomains under the same public suffix (e.g., `attacker.co.uk`).

Weakness classification

  • 2499f714-1537-4658-8207-48ae4bb9eae9: CWE-201
  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-201

Primary references