Missing Cryptographic Step Affecting deno package, versions <2.8.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RUST-DENO-17660657
- published27 Jun 2026
- disclosed16 Jun 2026
- creditUnknown
Introduced: 16 Jun 2026
NewCVE-2026-49440 (opens in a new tab)How to fix?
Upgrade deno to version 2.8.1 or higher.
Overview
deno is an a simple, modern and secure runtime for JavaScript and TypeScript that uses V8 and is built in Rust.
Affected versions of this package are vulnerable to Missing Cryptographic Step in the crypto.checkPrime and crypto.checkPrimeSync functions when the options.checks parameter is set to its default value of 0, causing the Miller-Rabin primality test to perform no rounds. An attacker can cause the acceptance of composite numbers as primes by supplying specially crafted numbers with prime factors above the trial division threshold. This can undermine cryptographic protocols if the application uses the result for security-sensitive operations.
Workaround
This vulnerability can be mitigated by explicitly passing a non-zero checks value (such as 64) when calling the affected functions, and by avoiding reliance on these functions to validate attacker-influenced numbers in security-critical code until patched.