CVE catalog
CVE-2026-55517
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket h
- Severity
- Medium · CVSS 4.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.32% · Oct 25, 2026
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCII. A response header containing non-visible-ASCII bytes (0x80-0xFF) caused a panic that aborted the entire Deno process. This vulnerability is fixed in 2.7.5.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | deno | Not reported | 2.7.5 | fixed |
| Cpe | deno | Not reported | 2.7.5 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | deno | cpe | Not reported | 2.7.5 | Not reported | Not reported | Not reported |
| Cpe | deno | cpe | Not reported | 2.7.5 | Not reported | NVD-CVE-2026-55517 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed: