CVE-2026-8927
Last modified
CVE-2026-8927 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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`.. EPSS estimates a 0.50% chance of exploitation in the next 30 days.
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`.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Haxx | Curl | >= 7.12.0, < 8.21.0 |
References
- https://curl.se/docs/CVE-2026-8927.htmlPatch, Vendor Advisory
- https://curl.se/docs/CVE-2026-8927.jsonVendor Advisory
- https://hackerone.com/reports/3744543Exploit, Issue Tracking, Third Party Advisory
- https://hackerone.com/reports/3744543Exploit, Issue Tracking, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
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