CVE-2025-9086

Out of bounds read for cookie path

HIGH
7.5
CVSS Score
Published: September 12, 2025 at 05:10 AM UTC
Updated: October 19, 2026 at 05:10 PM UTC
14 products affected across 3 vendorsDebian LinuxCurlRUGGEDCOM RST2428P Firmware

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

8.13.0 ≤ v < 8.16.01aea05a6c2699e80c75936d58569851555acd6038.13.08.14.08.14.18.15.0
Vendor states this is fixed in c6ae07c6a541e0e96d0040afb62b45dd37711300 (fixed)
Affected range stops below 8.14.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.16.0, so it looks safe — our inference, not a vendor statement
v < V3.3v < V4.0
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
Affected range stops below V4.0, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement
v < V3.3
Affected range stops below V3.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (7)

PatchVendor Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://curl.se/docs/CVE-2025-9086.html
Vendor Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://curl.se/docs/CVE-2025-9086.json
ExploitIssue TrackingThird Party Advisory
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
https://hackerone.com/reports/3294999
Mailing ListPatchThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2025/09/10/1
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2026/01/msg00002.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-089022.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-253495.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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