CVE catalog
CVE-2026-6276
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 secon
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.29% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | curl | sid | 8.23.0-1 | fixed |
| Debian | curl | forky | 8.22.0-1 | fixed |
| Debian | curl | trixie | 8.14.1-2+deb13u5 | fixed |
| Debian | curl | trixie-security | 8.14.1-2+deb13u7 | fixed |
| Debian | curl | bookworm | 7.88.1-10+deb12u15 | vulnerable |
| Debian | curl | bookworm-security | 7.88.1-10+deb12u5 | vulnerable |
| Cpe | curl | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | libcurl3t64-gnutls | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | libcurl4-doc | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | libcurl4-gnutls-dev | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | libcurl4-openssl-dev | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | libcurl4t64 | Not reported | 8.5.0-2ubuntu10.9 | fixed |
| Cpe | curl | Not reported | Not reported | vulnerable |
| Cpe | curl | Not reported | 8.20.0 | fixed |
| Cpe | curl | Not reported | 8.20.0 | fixed |
| Alpine | curl | 3.21 | 8.14.1-r3 | fixed |
| Alpine | curl | 3.22 | 8.14.1-r4 | fixed |
| Alpine | curl | 3.23 | 8.20.0-r0 | fixed |
| Alpine | curl | 3.24 | 8.20.0-r0 | fixed |
| Ubuntu | curl | 22.04 | 7.74.0-1.3ubuntu2 | vulnerable |
| Ubuntu | curl | 22.04 | 7.74.0-1.3ubuntu3 | vulnerable |
| Ubuntu | curl | 22.04 | 7.80.0-3 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.1 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.2 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.3 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.4 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.6 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.7 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.8 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.10 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.11 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.13 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.14 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.15 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.16 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.17 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.18 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.19 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.20 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.21 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.22 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.23 | vulnerable |
| Ubuntu | curl | 22.04 | 7.81.0-1ubuntu1.24 | fixed |
| Ubuntu | curl | 24.04 | 8.2.1-1ubuntu3 | vulnerable |
| Ubuntu | curl | 24.04 | 8.2.1-1ubuntu3.1 | vulnerable |
| Ubuntu | curl | 24.04 | 8.4.0-2ubuntu1 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu1 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu2 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu8 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu9 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.1 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.2 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.3 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.4 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.5 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.6 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.7 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.8 | vulnerable |
| Ubuntu | curl | 24.04 | 8.5.0-2ubuntu10.9 | fixed |
| Ubuntu | curl | 25.10 | 8.12.1-3ubuntu1 | vulnerable |
| Ubuntu | curl | 25.10 | 8.13.0-5ubuntu1 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-1ubuntu2 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-1ubuntu3 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-2ubuntu1 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-2ubuntu1.1 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-2ubuntu1.2 | vulnerable |
| Ubuntu | curl | 25.10 | 8.14.1-2ubuntu1.3 | fixed |
| Ubuntu | curl | 26.04 | 8.14.1-2ubuntu1 | vulnerable |
| Ubuntu | curl | 26.04 | 8.17.0-1ubuntu1 | vulnerable |
| Ubuntu | curl | 26.04 | 8.18.0-1ubuntu1 | vulnerable |
| Ubuntu | curl | 26.04 | 8.18.0-1ubuntu2 | vulnerable |
| Ubuntu | curl | 26.04 | 8.18.0-1ubuntu2.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | curl | source | sid | 8.20.0~rc3-1 | not yet assigned | Not reported | Not reported |
| Debian | curl | source | forky | 8.20.0~rc3-1 | not yet assigned | Not reported | Not reported |
| Debian | curl | source | trixie | 8.14.1-2+deb13u4 | not yet assigned | Not reported | Not reported |
| Debian | curl | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| Cpe | curl | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | libcurl3t64-gnutls | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | libcurl4-doc | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | libcurl4-gnutls-dev | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | libcurl4-openssl-dev | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | libcurl4t64 | cpe | Not reported | 8.5.0-2ubuntu10.9 | Not reported | Not reported | Not reported |
| Cpe | curl | cpe | Not reported | 8.20.0 | Not reported | Not reported | Not reported |
| Cpe | curl | cpe | Not reported | 8.20.0 | Not reported | NVD-CVE-2026-6276 | Not reported |
| Alpine | curl | apk | 3.21 | 8.14.1-r3 | Not reported | ALPINE-CVE-2026-6276 | Not reported |
| Alpine | curl | apk | 3.22 | 8.14.1-r4 | Not reported | ALPINE-CVE-2026-6276 | Not reported |
| Alpine | curl | apk | 3.23 | 8.20.0-r0 | Not reported | ALPINE-CVE-2026-6276 | Not reported |
| Alpine | curl | apk | 3.24 | 8.20.0-r0 | Not reported | ALPINE-CVE-2026-6276 | Not reported |
| Ubuntu | curl | deb | 22.04 | 7.81.0-1ubuntu1.24 | Not reported | UBUNTU-CVE-2026-6276 | Not reported |
| Ubuntu | curl | deb | 24.04 | 8.5.0-2ubuntu10.9 | Not reported | UBUNTU-CVE-2026-6276 | Not reported |
| Ubuntu | curl | deb | 25.10 | 8.14.1-2ubuntu1.3 | Not reported | UBUNTU-CVE-2026-6276 | Not reported |
| Ubuntu | curl | deb | 26.04 | 8.18.0-1ubuntu2.1 | Not reported | UBUNTU-CVE-2026-6276 | Not reported |
Notes
[bookworm] curl: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [curl]Affected
Details (6)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· amd64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· arm64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl3-gnutls]Affected
Source package: [curl]
Details (6)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· amd64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· arm64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl3-nss]Affected
Source package: [curl]
Details (4)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl4]Affected
Source package: [curl]
Details (6)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· amd64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· arm64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl4-doc]Affected
Source package: [curl]
Details (6)
7.88.1-10+deb12u15· all · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· all · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· all · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· all · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· all · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· all · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl4-gnutls-dev]Affected
Source package: [curl]
Details (6)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· amd64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· arm64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl4-nss-dev]Affected
Source package: [curl]
Details (4)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
- [libcurl4-openssl-dev]Affected
Source package: [curl]
Details (6)
7.88.1-10+deb12u15· amd64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u15· arm64 · bookwormAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· amd64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
8.14.1-2+deb13u2~bpo13+1· arm64 · bookworm-backportsAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· amd64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
7.88.1-10+deb12u5· arm64 · bookworm-securityAffected
nvd · curl · debian · bookworm; nvd · curl · debian · 12
[Debian 13 (Trixie)]
- [curl]Fixed
Details (5)
8.14.1-2+deb13u4· amd64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· arm64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· amd64 · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl3t64-gnutls]Fixed
Source package: [curl]
Details (5)
8.14.1-2+deb13u4· amd64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· arm64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· amd64 · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl4-doc]Fixed
Source package: [curl]
Details (5)
8.14.1-2+deb13u4· all · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· all · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· all · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· all · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· all · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl4-gnutls]Fixed
Source package: [curl]
Details (2)
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl4-gnutls-dev]Fixed
Source package: [curl]
Details (5)
8.14.1-2+deb13u4· amd64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· arm64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· amd64 · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl4-openssl-dev]Fixed
Source package: [curl]
Details (5)
8.14.1-2+deb13u4· amd64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· arm64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· amd64 · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
- [libcurl4t64]Fixed
Source package: [curl]
Details (5)
8.14.1-2+deb13u4· amd64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u4· arm64 · trixieFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.21.0-2~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
8.14.1-2+deb13u7· amd64 · trixie-securityFixed · Fixed:
8.14.1-2+deb13u4nvd · curl · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_3798-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-6276]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-6276]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-6276]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-6276]
- [https://security-tracker.debian.org/tracker/CVE-2026-6276]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6276.json]
- [https://ubuntu.com/security/notices/USN-8227-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-3167.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]