| Name | CVE-2026-50052 |
| 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6303-1 |
| Debian Bugs | 1138778 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| varnish (PTS) | bullseye | 6.5.1-1+deb11u3 | fixed |
| bullseye (security) | 6.5.1-1+deb11u5 | fixed | |
| bookworm, bookworm (security) | 7.1.1-2+deb12u1 | fixed | |
| trixie | 7.7.0-3 | vulnerable | |
| trixie (security) | 7.7.0-3+deb13u1 | fixed | |
| forky, sid | 7.7.3-3 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| varnish | source | bullseye | (not affected) | |||
| varnish | source | bookworm | (not affected) | |||
| varnish | source | trixie | 7.7.0-3+deb13u1 | DSA-6303-1 | ||
| varnish | source | (unstable) | 7.7.3-3 | 1138778 |
[bookworm] - varnish <not-affected> (Vulnerable code not present, introduced in 7.6)
[bullseye] - varnish <not-affected> (Vulnerable code not present, introduced in 7.6)
https://vinyl-cache.org/security/VSV00019.html
https://code.vinyl-cache.org/vinyl-cache/vinyl-cache/commit/dfc27fb4e7bf110945f5c145ce95b8de14ead77f (master)
https://code.vinyl-cache.org/vinyl-cache/vinyl-cache/commit/037031d429e3d309ae66ebabff33aa591402f20e (6.0)