Description
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.
Metrics
CVSS 4.0 2.3/10
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:N/R:A/V:D/RE:L/U:GreenWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| The Vinyl Cache Project | Vinyl Cache | 9.0.0 |
| The Vinyl Cache Project | Varnish Cache (pre split) | >= 7.6.0, <= 8.0.1; >= 6.0.14, <= 6.0.17 |
| Varnish Software | Varnish Cache by Varnish Software | >= 9.0.0, <= 9.0.2 |
References
Timeline
- Published
- Jun 3, 2026
- Last modified
- Jul 22, 2026
- NVD status
- Awaiting Analysis