5.3Medium

Haxx Curl

CVE-2026-6429

When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, libcurl could leak the password used for the first host to the followed-to host under certain circumstances.

What this means for your business

  • It affects Haxx Curl. It matters if your company, or a supplier that handles your data, runs it.
  • Code showing how to exploit it has been published, but real attacks have not been confirmed.
  • An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 43% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Haxx Curl, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Fastnexa security experts

Not sure if your company is exposed to CVE-2026-6429?

Tell us where you run Haxx Curl and a Fastnexa penetration tester will check whether this flaw, or others like it, can be used against your websites, apps and network.

The full test is free for our first 10 founding clients until 31 December 2026. See the offer

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Scoring

CVSS
5.3 (v3.1)
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-200
Assigned by
2499f714-1537-4658-8207-48ae4bb9eae9

Dates

Published
2026-05-13
Last modified
2026-09-15
Sources
NVD

Affected products

  • Haxx Curl7.14.0 - 8.20.0

As listed in the NVD configuration data. Not a statement about your estate.

References