Dashboard / CVE-2026-55517

CVE-2026-55517

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 59/100
Published: 2026-06-23 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Required
S: Unchanged
C: None
I: None
A: Low

Description

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
deno deno < 2.7.5

References & Advisories (1)

Bug Bounty Relevance

59 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

4.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS — Exploitation Probability

0.32%
Raw Score 0.003150
Percentile 24.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00315
2026-10-28
0.00315

Intelligence Sources

nvd ref →

External Links