CVE-2026-40396
varnishVulnerabilityCVSS 4.0
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 4.0 MEDIUM
Attack vectorNetwork (remote)
Attack complexityHigh
Privileges requiredNone
User interactionNone
ScopeChanged
Confidentiality impactNone
Integrity impactNone
Availability impactLow
Vector: AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
| Distribution | Package | Affected | Fixed version | Status |
|---|---|---|---|---|
| Ubuntu:14.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:Pro:16.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:Pro:18.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:Pro:20.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:Pro:22.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:24.04:LTS | varnish | - | - | affected (no fix yet) |
| Ubuntu:25.10 | varnish | - | - | affected (no fix yet) |
| Ubuntu:26.04:LTS | varnish | - | - | affected (no fix yet) |