CVE-2017-12939: A Remote Code Execution vulnerability was identified in all Windows versions of Unity Editor, e.g., before 5.3

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2017-12939 is a critical-severity flaw (CVSS 9.8) affecting unity editor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A Remote Code Execution vulnerability was identified in all Windows versions of Unity Editor, e.g., before 5.3.8p2, 5.4.x before 5.4.5p5, 5.5.x before 5.5.4p3, 5.6.x before 5.6.3p1, and 2017.x before 2017.1.0p4.

Why this priority

Critical severity
EPSS top 8%: very likely to be exploited
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.7% (top 8%)
CISA exploited list	No
Weakness	CWE-20
Published	2017-08-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: unity3d

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

Am I affected?

Timeline

2017-08-18 13:29 UTCPublished CVE record published
2026-06-17 01:04 UTCUpdated Record last modified

unity3d unity editor DOWNGRADE

Affected: 5.3.8 · 5.4.0 · 5.4.1 · 5.4.2 · 5.4.3 · 5.4.4 · 5.5.0 · 5.5.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.3.8

1. Check installed version

apt-cache policy unity-editor || rpm -q unity-editor || unity-editor --version

2. No fixed release: DOWNGRADE to a release before 5.3.8 (Debian / Ubuntu)

apt-cache madison unity-editor sudo apt install unity-editor=<VERSION_BEFORE_5.3.8> sudo apt-mark hold unity-editor

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list unity-editor sudo dnf downgrade unity-editor-<VERSION_BEFORE_5.3.8> sudo dnf versionlock add unity-editor

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-2017-12939?

unity editor: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-12939 being exploited?

CVE-2017-12939 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-2017-12939 affect?

CVE-2017-12939 affects unity editor. Severity is critical (CVSS 9.8). A Remote Code Execution vulnerability was identified in all Windows versions of Unity Editor, e.g., before 5.3.8p2, 5.4.x before 5.4.5p5, 5.5.x before 5.5.4p3, 5.6.x before 5.6.3p1, and 2017.x before 2017.1.0p4.

How urgent is CVE-2017-12939?

Priority 62/100. Critical severity; EPSS top 8%: very likely to be exploited; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities · Unity vulnerabilities

Related CVEs

CVE-2019-9197 HIGH 8.8 UPGRADE The com.unity3d.kharma protocol handler in Unity Editor 2018.3 allows remote attackers to execute arbitrary co

References

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