How severe is CVE-2021-3538?

CVE-2021-3538 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3538?

CVE-2021-3538 affects Satori Uuid. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3538?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-3538 published?

CVE-2021-3538 was published on 2021-06-02 and last updated on 2026-06-17.

CVE-2021-3538

CVE-2021-3538 is a critical-severity vulnerability in Satori Uuid with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-338
Affected product: Satori Uuid
Published: 2021-06-02
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-3538?: 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.
How severe is CVE-2021-3538?: CVE-2021-3538 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3538?: CVE-2021-3538 affects Satori Uuid. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3538?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-3538 published?: CVE-2021-3538 was published on 2021-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:satori:uuid:-:*:*:*:*:go:*:*

Other CWE-338 vulnerabilities

CVE-2026-56141 — Critical (CVSS 9.8): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429 account…
CVE-2026-3256 — Critical (CVSS 9.8): HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults…
CVE-2025-15604 — Critical (CVSS 9.8): Amon2 versions before 6.17 for Perl use an insecure random_string implementation for security functions. In versions…
CVE-2025-40926 — Critical (CVSS 9.8): Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session…
CVE-2026-2439 — Critical (CVSS 9.8): Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id…
CVE-2025-15578 — Critical (CVSS 9.8): Maypole versions from 2.10 through 2.13 for Perl generates session ids insecurely. The session id is seeded with the…

Browse all CWE-338 vulnerabilities →