How severe is CVE-2020-8659?

CVE-2020-8659 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-2020-8659 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8659?

CVE-2020-8659 primarily affects Cncf Envoy. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-8659?

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-2020-8659 published?

CVE-2020-8659 was published on 2020-03-04 and last updated on 2026-06-17.

CVE-2020-8659

CVE-2020-8659 is a high-severity vulnerability in Cncf Envoy 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-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Cncf Envoy
Published: 2020-03-04
Last modified: 2026-06-17

Description

CNCF Envoy through 1.13.0 may consume excessive amounts of memory when proxying HTTP/1.1 requests or responses with many small (i.e. 1 byte) chunks.

Frequently asked questions

What is CVE-2020-8659?: CNCF Envoy through 1.13.0 may consume excessive amounts of memory when proxying HTTP/1.1 requests or responses with many small (i.e. 1 byte) chunks.
How severe is CVE-2020-8659?: CVE-2020-8659 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-2020-8659 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8659?: CVE-2020-8659 primarily affects Cncf Envoy. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-8659?: 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-2020-8659 published?: CVE-2020-8659 was published on 2020-03-04 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:cncf:envoy:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_service_mesh:1.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

More vulnerabilities in Cncf Envoy

CVE-2020-8661 — High (CVSS 7.5): CNCF Envoy through 1.13.0 may consume excessive amounts of memory when responding internally to pipelined requests.
CVE-2020-8664 — Medium (CVSS 5.3): CNCF Envoy through 1.13.0 has incorrect Access Control when using SDS with Combined Validation Context. Using the same…

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