Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-07-03T06:11:15 libcurl: libcurl: Use-after-free vulnerability leading to Denial of Service 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-825

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.

A flaw was found in libcurl. This use-after-free vulnerability occurs when an application configures an HTTP/2 stream-dependency tree and then performs a sequence of operations involving `curl_easy_reset()` and `curl_easy_cleanup()`. During the final cleanup, libcurl attempts to access memory that has already been released. This can lead to application crashes, resulting in a Denial of Service (DoS).

This Moderate impact use-after-free flaw in libcurl can lead to application crashes and Denial of Service. It occurs when an application specifically configures an HTTP/2 stream-dependency tree and then performs a precise sequence of `curl_easy_reset()` and `curl_easy_cleanup()` operations, attempting to access already freed memory. This vulnerability requires a specific application programming pattern, limiting its exploitability in typical Red Hat deployments. Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Red Hat Enterprise Linux 8 Not affected dotnet8.0 Red Hat JBoss Core Services Affected libcurl-1.dll Red Hat JBoss Core Services Affected libcurl.so https://www.cve.org/CVERecord?id=CVE-2026-10536 https://nvd.nist.gov/vuln/detail/CVE-2026-10536 https://curl.se/docs/CVE-2026-10536.html https://curl.se/docs/CVE-2026-10536.json https://hackerone.com/reports/3751697