CVE-2026-8927
Critical
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`.
SeverityCritical
CVSS9.1
Exploit probability—
ProductHaxx Curl
PublishedJul 3, 2026
First seenJul 3, 2026
Weakness typeCWE-294CWE-294
How to fix
Update
- haxx curl8.21.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| haxx curl | 7.12.0 ≤ v < 8.21.0 | 8.21.0 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.