Is CVE-2026-9079 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-9079 being exploited in the wild.

How severe is CVE-2026-9079?

Informational severity, with a CVSS score of 0, published 3 July 2026.

Is there a fix for CVE-2026-9079?

A patch was published on 2026-06-24: Fixed in curl version 8.21.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-9079 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-9079?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-9079: curl libcurl stale proxy password leak

CVE-2026-9079 · Severity: info · CVSS 0 · Published 2026-07-03

A flaw in the libcurl library, which is widely used by applications to transfer data over various protocols, fails to properly clear proxy authentication credentials when instructed to do so. This could result in sensitive login information being unintentionally reused for subsequent data transfers. In practice, this means an application might accidentally send a user's proxy password to a destination that should not have access to it.

Quick answers

Is CVE-2026-9079 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-9079 being exploited in the wild.
How severe is CVE-2026-9079?: Informational severity, with a CVSS score of 0, published 3 July 2026.
Which products and versions are affected?: curl curl 8.8.0 to 8.20.0.
Is there a fix for CVE-2026-9079?: A patch was published on 2026-06-24: Fixed in curl version 8.21.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-9079 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-9079?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability in libcurl (CWE-522) occurs when the library is instructed to clear proxy authentication credentials but fails to do so. This results in the old credentials remaining in memory and being automatically applied to subsequent transfers using the same handle. The issue affects libcurl versions 8.8.0 through 8.20.0; the curl command-line tool is not affected. Attackers could potentially receive these leaked credentials if a transfer is directed to a malicious or unauthorized proxy/endpoint. The issue is fixed in version 8.21.0.

Affected products

curl curl 8.8.0 to 8.20.0

Timeline

2026-05-20: disclosed: Reported to the curl project via HackerOne.
2026-06-24: patched: Fixed in curl version 8.21.0.
2026-06-24: advisory: Project curl security advisory published.
2026-07-03: advisory: NVD publication date.

References

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