CVE-2026-49411: Deno is a JavaScript, TypeScript, and WebAssembly runtime

Routine

MEDIUM 6.5UPGRADE

CVE-2026-49411 is a medium-severity flaw (CVSS 6.5) 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 2.8.0, the Node.js compatibility TCP path checked the permission against the original hostname string before resolution and then did not re-check after resolution. A caller could therefore pass a numeric alias of an IP address (for example the decimal integer 2130706433 or the hex form 0x7f000001, both of which resolve to 127.0.0.1) and reach the denied destination through node:n

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 95%)
CISA exploited list	No
Weakness	CWE-284
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: >= 2.7.14 and < 2.8.0

Fixed in: 2.8.0

Safe to downgrade to: a release before 2.7.14

1. Check installed version

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

2. UPGRADE to 2.8.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 2.7.14 (Debian / Ubuntu)

apt-cache madison deno sudo apt install deno=<VERSION_BEFORE_2.7.14> sudo apt-mark hold deno

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list deno sudo dnf downgrade deno-<VERSION_BEFORE_2.7.14> sudo dnf versionlock add deno

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-49411?

deno: upgrade to 2.8.0. Exact commands for each OS are on this page.

Is CVE-2026-49411 being exploited?

CVE-2026-49411 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-2026-49411 affect?

CVE-2026-49411 affects deno. Severity is medium (CVSS 6.5). Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.0, the Node.js compatibility TCP path checked the permission against the original hostname string before resolution and then did not re-check after resolution. A caller

How urgent is CVE-2026-49411?

Priority 29/100. Public exploit reference

Software pages

Node.js vulnerabilities

Related CVEs

CVE-2026-49402 HIGH 8.1 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime
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-2026-49406 MEDIUM 5.5 UPGRADE Deno is a JavaScript, TypeScript, and WebAssembly runtime

References

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