PT-2026-35035 · Julia · Deno Jll

Published 2026-04-14 · Updated 2026-04-14

OSV

Versions of the package deno before 1.31.0 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the upgradeWebSocket function, which contains regexes in the form of /s*,s*/, used for splitting the Connection/Upgrade header. A specially crafted Connection/Upgrade header can be used to significantly slow down a web socket server.

Related Identifiers

JLSEC-2026-101

Affected Products

Deno Jll

References · 6

• https://osv.dev/vulnerability/JLSEC-2026-101 · Vendor Advisory
• https://github.com/denoland/deno/commit/cf06a7c7e672880e1b38598fe445e2c50b4a9d06 · Note
• https://github.com/denoland/deno/blob/2b247be517d789a37e532849e2e40b724af0918f/ext/http/01_http.js%23L395-L409 · Note
• https://github.com/denoland/deno/pull/17722 · Note
• https://github.com/denoland/deno/releases/tag/v1.31.0 · Note
• https://security.snyk.io/vuln/SNYK-RUST-DENO-3315970 · Note