Vulnerability Description
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`.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Haxx | Curl | >= 7.12.0, < 8.21.0 |
Related Weaknesses (CWE)
References
- https://curl.se/docs/CVE-2026-8927.htmlPatchVendor Advisory
- https://curl.se/docs/CVE-2026-8927.jsonVendor Advisory
- https://hackerone.com/reports/3744543ExploitIssue TrackingThird Party Advisory
- https://hackerone.com/reports/3744543ExploitIssue TrackingThird Party Advisory
FAQ
What is CVE-2026-8927?
CVE-2026-8927 is a vulnerability with a CVSS score of 9.1 (CRITICAL). 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 ...
How severe is CVE-2026-8927?
CVE-2026-8927 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-8927?
Check the references section above for vendor advisories and patch information. Affected products include: Haxx Curl.