CVE-2021-46703: In the IsolatedRazorEngine component of Antaris RazorEngine through 4.5.1-alpha001, an attacker can execute ar

Q: How do I fix CVE-2021-46703?

razorengine: upgrade to 4.5.1. Exact commands for each OS are on this page.

Q: Is CVE-2021-46703 being exploited?

CVE-2021-46703 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-2021-46703 affect?

CVE-2021-46703 affects razorengine. Severity is critical (CVSS 9.8). In the IsolatedRazorEngine component of Antaris RazorEngine through 4.5.1-alpha001, an attacker can execute arbitrary .NET code in a sandboxed environment (if users can externally control template contents). NOTE: This vulnerability only af

Q: How urgent is CVE-2021-46703?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-46703 is a critical-severity flaw (CVSS 9.8) affecting razorengine. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the IsolatedRazorEngine component of Antaris RazorEngine through 4.5.1-alpha001, an attacker can execute arbitrary .NET code in a sandboxed environment (if users can externally control template contents). NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Why this priority

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

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	1.9% (top 21%)
CISA exploited list	No
Published	2022-03-06
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: razorengine project

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

Am I affected?

Timeline

2022-03-06 06:15 UTCPublished CVE record published
2026-06-17 04:15 UTCUpdated Record last modified

razorengine project razorengine UPGRADE

Affected: < 4.5.1 · 4.5.1 alpha001

Fixed in: 4.5.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 4.5.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade razorengine

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-2021-46703?

razorengine: upgrade to 4.5.1. Exact commands for each OS are on this page.

Is CVE-2021-46703 being exploited?

CVE-2021-46703 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-2021-46703 affect?

CVE-2021-46703 affects razorengine. Severity is critical (CVSS 9.8). In the IsolatedRazorEngine component of Antaris RazorEngine through 4.5.1-alpha001, an attacker can execute arbitrary .NET code in a sandboxed environment (if users can externally control template contents). NOTE: This vulnerability only af

How urgent is CVE-2021-46703?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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