---
id: CVE-2023-46218
title: |-
  This flaw allows a malicious HTTP server to set "super cookies" in curl that
  are then passed back to more origins than what is otherwise allowed or
  possible
summary: |-
  This flaw allows a malicious HTTP server to set "super cookies" in curl that
  are then passed back to more origins than what is otherwise allowed or
  possible. This allows a site to set cookies that then would get sent to
  different and unr…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cvssSource: adp
vendor: curl
product: curl
affected:
  - curl >= 8.4.0 <= 8.4.0
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2025-05-28T16:38:08.000092Z'
exploitAvailable: true
published: '2023-12-07'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T00:04:49.559Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-46218'
references:
  - url: 'https://hackerone.com/reports/2212193'
  - url: 'https://curl.se/docs/CVE-2023-46218.html'
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3ZX3VW67N4ACRAPMV2QS2LVYGD7H2MVE/
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UOGXU25FMMT2X6UUITQ7EZZYMJ42YWWD/
  - url: 'https://lists.debian.org/debian-lts-announce/2023/12/msg00015.html'
  - url: 'https://www.debian.org/security/2023/dsa-5587'
  - url: 'https://security.netapp.com/advisory/ntap-20240125-0007/'
tags:
  - cve.org
  - exploit-available
epss: 0.01685
epssPercentile: 0.7667
ingestedAt: '2026-10-15T04:46:37.296Z'
---

## Overview

This flaw allows a malicious HTTP server to set "super cookies" in curl that
are then passed back to more origins than what is otherwise allowed or
possible. This allows a site to set cookies that then would get sent to
different and unrelated sites and domains.

It could do this by exploiting a mixed case flaw in curl's function that
verifies a given cookie domain against the Public Suffix List (PSL). For
example a cookie could be set with `domain=co.UK` when the URL used a lower
case hostname `curl.co.uk`, even though `co.uk` is listed as a PSL domain.

## Affected

- `curl >= 8.4.0 <= 8.4.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.