CVE-2021-3538: A flaw was found in github.com/satori/go.uuid in versions from commit 0ef6afb2f6cdd6cdaeee3885a95099c63f18fc8c

This week

CRITICAL 9.8REMOTEMITIGATE

CVE-2021-3538 is a critical-severity flaw (CVSS 9.8) affecting uuid. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in github.com/satori/go.uuid in versions from commit 0ef6afb2f6cdd6cdaeee3885a95099c63f18fc8c to d91630c8510268e75203009fe7daf2b8e1d60c45. Due to insecure randomness in the g.rand.Read function the generated UUIDs are predictable for an attacker.

Why this priority

Critical severity
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	2.3% (top 17%)
CISA exploited list	No
Weakness	CWE-338
Published	2021-06-02
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: satori

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

Am I affected?

Timeline

2021-06-02 14:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

satori uuid MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2021-3538?

uuid: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-3538 being exploited?

CVE-2021-3538 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-2021-3538 affect?

CVE-2021-3538 affects uuid. Severity is critical (CVSS 9.8). A flaw was found in github.com/satori/go.uuid in versions from commit 0ef6afb2f6cdd6cdaeee3885a95099c63f18fc8c to d91630c8510268e75203009fe7daf2b8e1d60c45. Due to insecure randomness in the g.rand.Read function the generated UUIDs are predi

How urgent is CVE-2021-3538?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

GitHub vulnerabilities

Related CVEs

CVE-2026-41907 HIGH 7.5 UPGRADE uuid is for the creation of RFC9562 (formerly RFC4122) UUIDs
CVE-2026-41988 LOW 3.2 UPGRADE uuid before 14.0.0 can make unexpected writes when external output buffers are used, and the UUID version is 3

References

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