---
id: CVE-2026-10536
title: |-
  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…
summary: |-
  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…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-416
  - CWE-825
vendor: haxx
product: curl
affected:
  - 'curl >= 7.88.0, < 8.21.0'
patched:
  - curl 8.21.0
published: '2026-07-03'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T07:16:25.137'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-10536'
references:
  - url: 'https://curl.se/docs/CVE-2026-10536.html'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'https://curl.se/docs/CVE-2026-10536.json'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'https://hackerone.com/reports/3751697'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'https://hackerone.com/reports/3751697'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-10536.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-10536'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2496766'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-10536'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-10536'
  - url: 'https://access.redhat.com/errata/RHSA-2026:41240'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
  - score-dispute
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-07-06T18:28:36.822614Z'
epss: 0.00598
epssPercentile: 0.47027
ingestedAt: '2026-07-04T04:55:39.409Z'
scores:
  nvd: 9.8
  vendor: 4.7
---

## Overview

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

- `curl >= 7.88.0, < 8.21.0`

## Remediation

Upgrade past the affected range:

- `curl 8.21.0`

## Vendor advisories

- **RHSA-2026:41240** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:41240)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-10536.json)