What is CVE-2026-49440?

CVE-2026-49440 is a high-severity vulnerability in Deno, classified under Missing Cryptographic Step. CVSS score: 7.4/10. Published 2026-06-23.

How severe is CVE-2026-49440?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Deno

CVE-2026-49440

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 opti…

EPSS: 0.001 (4.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Deno
Denoland Deno — versions < 2.8.1

Weakness classification (CWE)

CWE-325 — Missing Cryptographic Step

References

security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
security-advisories@github.com (x_refsource_MISC, Issue Tracking)

Frequently asked questions

What is CVE-2026-49440?: CVE-2026-49440 is a high-severity vulnerability in Deno, classified under Missing Cryptographic Step. CVSS score: 7.4/10. Published 2026-06-23.
How severe is CVE-2026-49440?: High severity. CVSS v3 base score is 7.4 out of 10.