# CVE-2026-6429: netrc credential leak with reused proxy connection

> An attacker can steal netrc credentials from the first host when libcurl follows HTTP redirects to a different host.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 May 2026
- **Updated:** 15 Sep 2026
- **Also known as:** ALPINE-CVE-2026-6429, AZL-86661, AZL-86688, BELL-CVE-2026-6429, CURL-CVE-2026-6429, DEBIAN-CVE-2026-6429, ECHO-2ec8-1a62-f90d, GHSA-2pvc-5qw9-h3ph, JLSEC-2026-1208, MINI-6hqm-ww8p-h58r, MINI-fjgf-3rf4-f8px, ROOT-OS-DEBIAN-11-CVE-2026-6429, ROOT-OS-DEBIAN-12-CVE-2026-6429, UBUNTU-CVE-2026-6429

## What is CVE-2026-6429?

CVE-2026-6429 is a medium-severity vulnerability in Haxx Curl, published on 13 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-6429?

It affects 1 product.


Products: Haxx Curl.

## How do I fix CVE-2026-6429?

Upgrade to a fixed version.

## Is CVE-2026-6429 being exploited?

There is no known exploitation of CVE-2026-6429 in the wild and no public exploit code.

## Other vulnerabilities in Haxx Curl

- [CVE-2026-19931](https://insights.sbomify.com/CVE-2026-19931/): Negotiate ambient user conn reuse (critical 9.8)
- [CVE-2026-10536](https://insights.sbomify.com/CVE-2026-10536/): HTTP/2 stream-dependency tree UAF (critical 9.8)
- [CVE-2026-11856](https://insights.sbomify.com/CVE-2026-11856/): cross-origin Digest auth state leak (critical 9.8)
- [CVE-2026-8925](https://insights.sbomify.com/CVE-2026-8925/): SASL double-free (critical 9.8)
- [CVE-2026-9079](https://insights.sbomify.com/CVE-2026-9079/): stale proxy password leak (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6429 and fix it if it is affected.

What it is: CVE-2026-6429 is a medium-severity vulnerability in Haxx Curl, published on 13 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-6429 in the wild and no public exploit code.

Affected product: Haxx Curl. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-6429/ (Markdown: https://insights.sbomify.com/CVE-2026-6429/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6429
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6429
- OSV: https://osv.dev/vulnerability/CVE-2026-6429

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6429/
Summaries are generated and may contain mistakes; the official description above is the record.