cURL Security Update Due October 14: Prepare Your API Tests

cURL has brought forward its next release after receiving a report of a HIGH-severity vulnerability. On October 7, maintainer Daniel Stenberg announced that version 8.23.0 is planned for October 14, 2026, with fixes for 22 vulnerabilities. The HIGH-severity issue is identified as CVE-2026-92392; its technical details are scheduled for disclosure alongside the release. See the maintainer’s announcement .

For developers who use cURL to check websites, call APIs, or troubleshoot staging environments, this is a useful moment to prepare. You can identify your installations and assemble a few repeatable requests now, then check that they still behave as expected after updating.

Our cURL command builder helps prepare those requests. If your staging site uses Apache password protection, the htpasswd generator can also help you create a dedicated test account.

What is known, and what is still pending?

As of October 8, the announcement confirms the planned release date, the number of fixes, and the identifier and severity of the most serious issue. It does not disclose the conditions that trigger that flaw or the affected version range. It also says updated Rock-solid curl releases are planned at the same time.

That leaves an important limit: the announcement alone cannot tell you whether a particular installation is exposed. Check the official cURL vulnerability list  and your software supplier’s advisory when the details become available. The examples below are ordinary functionality checks, not tests for the undisclosed vulnerability.

Find the cURL installation your work actually uses

Start in the environment where you normally run requests:

curl --version

The output identifies cURL, its linked libcurl, and supporting libraries, followed by supported protocols and features. The cURL manual’s version option  explains the fields.

In PowerShell, use curl.exe --version to avoid a possible alias for another command. Microsoft’s bundled cURL is maintained separately from the builds distributed by the cURL project, as the Windows installation notes  explain.

For your own update plan, make a short inventory:

Run the version check inside each relevant terminal or container. Treat an application that embeds libcurl as a separate item: the output from your terminal’s executable does not establish which library that application uses.

Prepare one small request you can repeat

Choose a read-only endpoint whose expected response you know. In the cURL command builder, select GET, enter the URL, and enable Accept JSON responses if appropriate. Copy the generated command and keep it with a note describing the expected status and response fields.

For example:

curl \
  --request 'GET' \
  --url 'https://example.com/api/status' \
  --header 'Accept: application/json'

The URL is illustrative; replace it with an endpoint you control. These multiline examples use POSIX shell syntax, including Bash and Zsh, rather than PowerShell or Windows Command Prompt syntax.

To record response headers separately, add these options manually to the copied command:

curl \
  --request 'GET' \
  --url 'https://example.com/api/status' \
  --header 'Accept: application/json' \
  --dump-header 'before-update-headers.txt' \
  --output 'before-update-body.json'

--dump-header saves received headers and --output saves the body; both are documented in the cURL option reference . Choose unused filenames because these outputs can overwrite existing files. The builder does not currently provide dedicated controls for these two options.

After updating, repeat the request with filenames beginning after-update-. Compare the status, relevant headers, and expected body fields. Dates, request IDs, and other changing values may legitimately differ. Successful requests help check compatibility; they do not establish that a security fix is installed.

The builder generates command text locally in your browser. It does not contact the endpoint or update cURL. Running the copied command in your terminal sends the request.

Include your staging site’s authentication check

If you already protect an Apache staging site with HTTP Basic authentication, include both an unauthenticated request and a request using a dedicated test account in your checks.

The htpasswd generator creates a username:hash entry for the server’s password file. Choose bcrypt when your server supports it, install the entry outside the public website directory, and configure Apache to use it. Generating an entry alone does not enable access control; follow the tool’s configuration example and the Apache authentication guide .

For a test user named release-check, a terminal request can look like this:

curl --user 'release-check' \
  --url 'https://example.com/private/'

cURL prompts for the password when you supply only the username. Enter the original password, not the generated hash. Use HTTPS because Basic authentication does not encrypt credentials itself. See cURL’s HTTP authentication guide .

Check that the protected resource rejects an unauthenticated request and returns the expected content for the test account. Keep credentials out of saved examples and review captured headers before sharing them, since responses can contain cookies. This checks your staging setup; password protection is not a remedy for a vulnerability in cURL.

When the release arrives

Read the published advisories to establish which versions and configurations are affected. Obtain the applicable update through the supplier responsible for each installation, then repeat your version and functionality checks in those same environments. For a supplier-maintained package, consult its security notice as well as the upstream version number.

Having a small, documented request ready makes that follow-up easier. Start with the cURL command builder, or use our cURL command guide for more examples covering request bodies, redirects, and timeouts.