| Summary | Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a "workspace overflow" denial of service (daemon panic) for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the HTTP/1 request is repurposed as stream zero. During the upgrade, a buffer allocation is made to reserve space to send frames to the client. This allocation would split the original workspace, and depending on the amount of prefetched data, the next fetch could perform a pipelining operation that would run out of workspace. |
|---|---|
| Publication Date | April 13, 2026, 5:16 a.m. |
| Registration Date | April 15, 2026, 11:37 a.m. |
| Last Update | April 17, 2026, 11:35 p.m. |
| CVSS3.1 : HIGH | |
| スコア | 7.5 |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 攻撃元区分(AV) | ネットワーク |
| 攻撃条件の複雑さ(AC) | 低 |
| 攻撃に必要な特権レベル(PR) | 不要 |
| 利用者の関与(UI) | 不要 |
| 影響の想定範囲(S) | 変更なし |
| 機密性への影響(C) | なし |
| 完全性への影響(I) | なし |
| 可用性への影響(A) | 高 |
| Configuration1 | or higher | or less | more than | less than | |
| cpe:2.3:a:varnish-software:varnish_enterprise:*:*:*:*:*:*:*:* | 6.0.15 | ||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r1:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r10:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r2:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r3:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r4:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r5:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r6:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r7:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r8:*:*:*:*:*:* | |||||
| cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r9:*:*:*:*:*:* | |||||
| cpe:2.3:a:vinyl-cache:vinyl_cache:9.0.0:*:*:*:*:*:*:* | |||||