CVE-2026-6276
Fixed in a distro release EPSS <1%CVSS 7.5
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.
Products: curl
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.21 | curl | 8.14.1-r3 |
| Alpine 3.22 | curl | 8.14.1-r4 |
| Alpine 3.23 | curl | 8.20.0-r0 |
| Alpine 3.24 | curl | 8.20.0-r0 |
| Chainguard | libcurl4 | no fix |
| Debian 12 | curl | no fix |
| Debian 13 | curl | 8.14.1-2+deb13u4 |
| Debian 14 | curl | 8.20.0~rc3-1 |
| Red Hat hummingbird 1 | curl | 0:8.20.0-0.1.hum1 |
| Red Hat hummingbird 1 | libcurl | 0:8.20.0-0.1.hum1 |
| Red Hat hummingbird 1 | libcurl-devel | 0:8.20.0-0.1.hum1 |
| Red Hat hummingbird 1 | libcurl-minimal | 0:8.20.0-0.1.hum1 |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | curl | 8.14.1-150700.7.23.1 |
| SUSE Linux Enterprise Server 16.0 | curl | 8.14.1-160000.6.1 |
| SUSE Linux Enterprise Server 16.0 | curl-mini | 8.14.1-160000.6.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | curl | 8.0.1-11.123.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | curl | 8.14.1-160000.6.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | curl-mini | 8.14.1-160000.6.1 |
| SUSE Linux Micro 6.2 | curl | 8.14.1-160000.6.1 |
| Ubuntu 22.04 LTS | curl | 7.81.0-1ubuntu1.24 |
| Ubuntu 24.04 LTS | curl | 8.5.0-2ubuntu10.9 |
| Ubuntu 25.10 | curl | 8.14.1-2ubuntu1.3 |
| Ubuntu 26.04 LTS | curl | 8.18.0-1ubuntu2.1 |
| Wolfi | libcurl4 | no fix |
| openSUSE Leap 16.0 | curl | 8.14.1-160000.6.1 |
| openSUSE Tumbleweed | curl | 8.20.0-1.1 |