CVE-2021-46461: njs through 0.7.0, used in NGINX, was discovered to contain an out-of-bounds array access via njs_vmcode_typeo

Q: How do I fix CVE-2021-46461?

njs: upgrade to newer than 0.7.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-46461 being exploited?

CVE-2021-46461 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-2021-46461 affect?

CVE-2021-46461 affects njs. Severity is critical (CVSS 9.8). njs through 0.7.0, used in NGINX, was discovered to contain an out-of-bounds array access via njs_vmcode_typeof in /src/njs_vmcode.c.

Q: How urgent is CVE-2021-46461?

Priority 71/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2021-46461 is a critical-severity flaw (CVSS 9.8) affecting njs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

njs through 0.7.0, used in NGINX, was discovered to contain an out-of-bounds array access via njs_vmcode_typeof in /src/njs_vmcode.c.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.1% (top 12%)
CISA exploited list	No
Weakness	CWE-119
Published	2022-02-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nginx

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-02-14 22:15 UTCPublished CVE record published
2026-06-17 04:14 UTCUpdated Record last modified

nginx njs UPGRADE

Affected: <= 0.7.0

Fixed in: newer than 0.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 0.7.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade njs

Note

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

Exact fixes by distribution

Fedora 46 · nemo · FIXED · 6.8.0-1.fc46 · FEDORA-2026-0edead723f · source

sudo dnf upgrade --advisory=FEDORA-2026-0edead723f

Fedora ELN · composer · FIXED · 2.11.1-1.eln159 · FEDORA-2026-cb4f992456 · source

sudo dnf upgrade --advisory=FEDORA-2026-cb4f992456

Alpine 3.20 · nginx · FIXED · nginx-1.20.2-r2

apk add --upgrade nginx apk info -v nginx

Alpine 3.20 · njs · FIXED · njs-0.7.1-r0

apk add --upgrade njs apk info -v njs

Alpine 3.21 · nginx · FIXED · nginx-1.20.2-r2

apk add --upgrade nginx apk info -v nginx

Alpine 3.21 · njs · FIXED · njs-0.7.1-r0

apk add --upgrade njs apk info -v njs

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/nginx/njs/issues/450

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-2021-46461?

njs: upgrade to newer than 0.7.0. Exact commands for each OS are on this page.

Is CVE-2021-46461 being exploited?

CVE-2021-46461 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-2021-46461 affect?

CVE-2021-46461 affects njs. Severity is critical (CVSS 9.8). njs through 0.7.0, used in NGINX, was discovered to contain an out-of-bounds array access via njs_vmcode_typeof in /src/njs_vmcode.c.

How urgent is CVE-2021-46461?

Priority 71/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

nginx vulnerabilities

Related CVEs

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CVE-2023-27729 HIGH 7.5 DOWNGRADE Nginx NJS v0.7.10 was discovered to contain an illegal memcpy via the function njs_vmcode_return at src/njs_vm
CVE-2023-27728 HIGH 7.5 DOWNGRADE Nginx NJS v0.7.10 was discovered to contain a segmentation violation via the function njs_dump_is_recursive at
CVE-2023-27727 HIGH 7.5 DOWNGRADE Nginx NJS v0.7.10 was discovered to contain a segmentation violation via the function njs_function_frame at sr

References

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