CVE-2026-82209

HIGH CVSS 3.1: 8.2 EPSS 0.54%
Updated Sep 15, 2026
Curl
Parameter Value
CVSS 8.2 (HIGH)
Affected Versions 7.46.0 — 8.22.0
Fixed In 8.22.0
Type CWE-201, CWE-201 Information Exposure Through Sent Data
Vendor Curl
Public PoC No

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`).

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
Low
Partial data leak
Integrity
High
Complete data modification
Availability
None
No disruption

CVSS Vector v3.1

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Haxx Curl
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
7.46.0 8.22.0