Vulnerability in The Vinyl Cache Project Varnish (Pre Split)
CVE-2026-50052
In Vinyl Cache before 9.0.1 and Varnish Cache before 9.0.3, a deficiency in HTTP/2 request parsing can be exploited to launch a backend request desync attack (request smuggling), which in turn can be used for cache poisoning, authentication bypass, or possibly even information disclosure and manipulation. The attack vector only exists if HTTP/2 support is enabled by setting the feature parameter to contain +http2. HTTP/2 support is disabled by default.
Vulnerability class: HTTP Request Smuggling
Published · last modified .
EPSS exploit prediction
EPSS: 0.005 (38.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- The Vinyl Cache Project Varnish (Pre Split) — versions 7.6.0, 8.0.2, 6.0.14
- The Vinyl Cache Project — versions 9.0.0, 9.0.1
- Varnish Software Cache By — versions 9.0.0, 9.0.3