CVE intelligence

CVE-2026-8927

Vulnerability intelligence

Published Jul 3, 2026Sources checked Oct 28, 2026

9.1CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-8927 and is rated Critical severity with a CVSS score of 9.1. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Sep 28, 2026

USN-8487-1 fixed vulnerabilities in curl.

Ubuntu Security Notices guidance

Vendor revision: Sep 24, 2026

This issue was previously fixed in USN-8487-1, but that fix was incomplete for Ubuntu 16.04 LTS.

Microsoft Security Response Center guidance

Vendor revision: Aug 13, 2026

CBL-Mariner Releases

Vendor-listed releases

8.11.1-10

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-8927?

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

Source: NVD