| Name | CVE-2026-6276 |
| 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| curl (PTS) | bullseye | 7.74.0-1.3+deb11u13 | vulnerable |
| bullseye (security) | 7.74.0-1.3+deb11u16 | vulnerable | |
| bookworm | 7.88.1-10+deb12u14 | vulnerable | |
| bookworm (security) | 7.88.1-10+deb12u5 | vulnerable | |
| trixie | 8.14.1-2+deb13u3 | vulnerable | |
| forky | 8.20.0-1 | fixed | |
| sid | 8.20.0-2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| curl | source | (unstable) | 8.20.0~rc3-1 |
[trixie] - curl <no-dsa> (Minor issue)
[bookworm] - curl <no-dsa> (Minor issue)
[bullseye] - curl <postponed> (Minor issue; can be fixed in next update)
https://curl.se/docs/CVE-2026-6276.html
Introduced by: https://github.com/curl/curl/commit/e15e51384a423be31318b3c9c7d612a1aae661fd (curl-7_71_0)
Fixed by: https://github.com/curl/curl/commit/3a19987a87f393d9394fe5acc7643f6c263c92db (rc-8_20_0-3)