CVE-2026-49440
High · 7.4CVSS
7.4
EPSS
0.2%
Published
Jun 23, 2026
CISA due date
—
The record
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, node:crypto.checkPrime(candidate[, options][, callback]) and crypto.checkPrimeSync(candidate[, options]) ran no Miller-Rabin rounds at all when the caller left options.checks at its default of 0. In that mode, the only test applied to the candidate was trial division by the primes up to 17,863. Any composite whose smallest prime factor exceeds that bound — for example the product of two primes just above it, such as 17,881 × 17,891 — was reported as true ("probably prime"). The same divergence affected the lower-level op_node_check_prime / op_node_check_prime_bytes paths that the polyfill calls into. This vulnerability is fixed in 2.8.1.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| crates.io | deno | 0 | 2.8.1 |
Related vulnerabilities
- GHSA-9xg4-qhm4-g43w Deno: Miller-Rabin Primality Test Allows Zero Rounds Same vulnerability
- CVE-2026-55517 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49860 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49983 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49401 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49411 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49402 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno
- CVE-2026-49406 Deno is a JavaScript, TypeScript, and WebAssembly runtime. Also affects deno