CVE-2025-9086

7.5 HIGH
Published: September 12, 2025 Modified: November 04, 2025

Description

1. A cookie is set using the `secure` keyword for `https://target` 2. curl is redirected to or otherwise made to speak with `http://target` (same hostname, but using clear text HTTP) using the same cookie set 3. The same cookie name is set - but with just a slash as path (`path='/'`). Since this site is not secure, the cookie *should* just be ignored. 4. A bug in the path comparison logic makes curl read outside a heap buffer boundary The bug either causes a crash or it potentially makes the comparison come to the wrong conclusion and lets the clear-text site override the contents of the secure cookie, contrary to expectations and depending on the memory contents immediately following the single-byte allocation that holds the path. The presumed and correct behavior would be to plainly ignore the second set of the cookie since it was already set as secure on a secure host so overriding it on an insecure host should not be okay.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://curl.se/docs/CVE-2025-9086.html
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://curl.se/docs/CVE-2025-9086.json
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://hackerone.com/reports/3294999
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
http://www.openwall.com/lists/oss-security/2025/09/10/1
Source: af854a3a-2127-422b-91ae-364da2661108

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.0%
5th percentile
Exploitation Status
Not in CISA KEV