CVE-2025-9086

HIGH EPSS 66.9%
Published Sep 12, 20259mo ago · Modified Jun 17, 20261w ago
7.5 CVSS 3.1
High
Find Similar
Published Sep 12, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
66.9% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 2

VendorProductVersionRange
haxxcurl*≥8.13.0  –  <8.16.0
debiandebian_linux11.0any

References 7

  • openwall.com http://www.openwall.com/lists/oss-security/2025/09/10/1
    Mailing ListPatchThird Party Advisory
  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-089022.html
  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-253495.html
  • curl.se https://curl.se/docs/CVE-2025-9086.html
    PatchVendor Advisory
  • curl.se https://curl.se/docs/CVE-2025-9086.json
    Vendor Advisory
  • hackerone.com https://hackerone.com/reports/3294999
    ExploitIssue TrackingThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2026/01/msg00002.html
    Mailing ListThird Party Advisory

Remediation

  • openwall.com http://www.openwall.com/lists/oss-security/2025/09/10/1
    Mailing ListPatchThird Party Advisory
  • curl.se https://curl.se/docs/CVE-2025-9086.html
    PatchVendor Advisory