By A bug was discovered in the most recent release of Varnish Enterprise (6.0.16r2), released on September 9th 2025.
This release adds new features, including a new way of handling cache of objects which would otherwise not be cacheable (with neither TTL nor grace set).
However this new feature release unfortunately also introduced a regression, causing Varnish to panic and the process to die. The bug, discovered on September 15th, was declared important and the release 6.0.16r2 was pulled from the packagecloud repositories.
The Varnish Plus repository on packagecloud now shows 6.0.16r1 as most recent package.
Please note that this bug only affects the Enterprise version of Varnish. The open source version of Varnish Cache is – to the current knowledge – not affected.
It might however take some time until the (CDN-spread) repositories world-wide are updated.
Users having already installed Varnish 6.0.16r2 are advised to downgrade to 6.0.16r1, which seems unaffected by the regression.
The Varnish team has in the meantime already identified the source of the bug and are working on releasing a new package with a fix.
Update: The fixed version 6.0.16r3 was released on September 18th 2025.
