CVE-2026-49402: Deno is a JavaScript, TypeScript, and WebAssembly runtime

Q: How do I fix CVE-2026-49402?

deno: upgrade to 2.7.10. Exact commands for each OS are on this page.

Q: Is CVE-2026-49402 being exploited?

CVE-2026-49402 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-49402 affect?

CVE-2026-49402 affects deno. Severity is high (CVSS 8.1). Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.10, Deno's node:child_process implementation provided an escapeShellArg() helper used when callers passed shell: true to spawn / spawnSync / exec and friends. On Window

Q: How urgent is CVE-2026-49402?

Priority 48/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 8.1REMOTEUPGRADE

CVE-2026-49402 is a high-severity flaw (CVSS 8.1) affecting deno. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.10, Deno's node:child_process implementation provided an escapeShellArg() helper used when callers passed shell: true to spawn / spawnSync / exec and friends. On Windows, the helper failed to quote arguments that contained cmd.exe metacharacters and did not neutralize % (which cmd.exe expands even inside double-quoted strings). An attacker who controlled any portion of an arg

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 62%)
CISA exploited list	No
Weakness	CWE-78
Published	2026-06-23
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: deno

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-23 18:18 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

deno deno UPGRADE

Affected: < 2.7.10

Fixed in: 2.7.10

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy deno || rpm -q deno || deno --version

2. UPGRADE to 2.7.10 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade deno

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade deno

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-49402?

deno: upgrade to 2.7.10. Exact commands for each OS are on this page.

Is CVE-2026-49402 being exploited?

CVE-2026-49402 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-49402 affect?

CVE-2026-49402 affects deno. Severity is high (CVSS 8.1). Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.10, Deno's node:child_process implementation provided an escapeShellArg() helper used when callers passed shell: true to spawn / spawnSync / exec and friends. On Window

How urgent is CVE-2026-49402?

Priority 48/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities

Related CVEs

CVE-2026-44726 HIGH 7.4 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime
CVE-2026-49440 HIGH 7.4 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime
CVE-2026-49401 HIGH 7.3 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime
CVE-2026-49411 MEDIUM 6.5 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime
CVE-2026-49406 MEDIUM 5.5 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime

References

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