How severe is CVE-2021-3690?

CVE-2021-3690 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-3690 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3690?

CVE-2021-3690 primarily affects Redhat Fuse. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3690?

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

When was CVE-2021-3690 published?

CVE-2021-3690 was published on 2022-08-23 and last updated on 2026-06-17.

CVE-2021-3690

CVE-2021-3690 is a high-severity vulnerability in Redhat Fuse with a CVSS 3.x base score of 7.5. 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-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: Redhat Fuse
Published: 2022-08-23
Last modified: 2026-06-17

Description

A flaw was found in Undertow. A buffer leak on the incoming WebSocket PONG message may lead to memory exhaustion. This flaw allows an attacker to cause a denial of service. The highest threat from this vulnerability is availability.

Frequently asked questions

What is CVE-2021-3690?: A flaw was found in Undertow. A buffer leak on the incoming WebSocket PONG message may lead to memory exhaustion. This flaw allows an attacker to cause a denial of service. The highest threat from this vulnerability is availability.
How severe is CVE-2021-3690?: CVE-2021-3690 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-3690 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3690?: CVE-2021-3690 primarily affects Redhat Fuse. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3690?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-3690 published?: CVE-2021-3690 was published on 2022-08-23 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:redhat:fuse:1.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:integration_camel_k:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:integration_camel_quarkus:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:-:*:*:*:text-only:*:*:*
cpe:2.3:a:redhat:openshift_application_runtimes:-:*:*:*:text-only:*:*:*
cpe:2.3:a:redhat:single_sign-on:-:*:*:*:text-only:*:*:*
cpe:2.3:a:redhat:undertow:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:7.3:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_enterprise_application_platform:7.4:*:*:*:*:*:*:*

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