Vulnerability · Published Jul 3, 2026 · Assigned by curl
CVE-2026-10536HTTP/2 stream-dependency tree UAF
Critical 9.8
In plain English
A critical-severity use-after-free in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | curl | 8.12.1-4.el10_2.7 | ALSA-2026:80512 |
| AlmaLinux:10 | libcurl | 8.12.1-4.el10_2.7 | ALSA-2026:80512 |
| AlmaLinux:10 | libcurl-devel | 8.12.1-4.el10_2.7 | ALSA-2026:80512 |
| AlmaLinux:10 | libcurl-minimal | 8.12.1-4.el10_2.7 | ALSA-2026:80512 |
| Alpine:v3.23 | curl | 8.22.0-r0 | ALPINE-CVE-2026-10536 |
| Alpine:v3.24 | curl | 8.21.0-r0 | ALPINE-CVE-2026-10536 |
| Debian:12 | curl | no fix listed | DEBIAN-CVE-2026-10536 |
| Debian:13 | curl | no fix listed | DEBIAN-CVE-2026-10536 |
| Debian:14 | curl | 8.21.0~rc2-1 | DEBIAN-CVE-2026-10536 |
| Rocky Linux:10 | curl | 0:8.12.1-4.el10_2.7 | RLSA-2026:80512 |
| Ubuntu:24.04:LTS | curl | 8.5.0-2ubuntu10.11 | UBUNTU-CVE-2026-10536 |
| Ubuntu:25.10 | curl | 8.14.1-2ubuntu1.5 | UBUNTU-CVE-2026-10536 |
| Ubuntu:26.04:LTS | curl | 8.18.0-1ubuntu2.3 | UBUNTU-CVE-2026-10536 |
Affected products (as reported)
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H