Use-After-Free in libcurl during cleanup after stream-dependency reset
CVE-2026-10536 Published on July 3, 2026

HTTP/2 stream-dependency tree UAF
A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or `CURLOPT_STREAM_DEPENDS_E`, subsequently invokes `curl_easy_reset()`, and finally terminates the handle with `curl_easy_cleanup()`. During this final cleanup phase, libcurl attempts to access and modify an internal structure that was already freed during the reset operation.

NVD

Vulnerability Analysis

CVE-2026-10536 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Dangling pointer Vulnerability?

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

CVE-2026-10536 has been classified to as a Dangling pointer vulnerability or weakness.


Products Associated with CVE-2026-10536

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-10536 are published in these products:

Haxx Curl
 
Canonical Ubuntu Linux
 
Red Hat Http Server
 

Affected Versions

curl: curl: curl:

Exploit Probability

EPSS
0.60%
Percentile
46.46%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.