CVE-2026-6276
High
Description
Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.
SeverityHigh
CVSS7.5
Exploit probability—
ProductHaxx Curl
PublishedMay 13, 2026
First seenMay 13, 2026
Weakness typeCWE-346CWE-346
How to fix
Update
- haxx curl8.20.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| haxx curl | 7.71.0 ≤ v < 8.20.0 | 8.20.0 |
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