How severe is CVE-2020-35470?

CVE-2020-35470 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-35470 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-35470?

CVE-2020-35470 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-35470?

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-2020-35470 published?

CVE-2020-35470 was published on 2020-12-15 and last updated on 2026-06-17.

CVE-2020-35470

CVE-2020-35470 is a high-severity vulnerability in Envoyproxy Envoy with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 5.8
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Envoyproxy Envoy
Published: 2020-12-15
Last modified: 2026-06-17

Description

Envoy before 1.16.1 logs an incorrect downstream address because it considers only the directly connected peer, not the information in the proxy protocol header. This affects situations with tcp-proxy as the network filter (not HTTP filters).

Frequently asked questions

What is CVE-2020-35470?: Envoy before 1.16.1 logs an incorrect downstream address because it considers only the directly connected peer, not the information in the proxy protocol header. This affects situations with tcp-proxy as the network filter (not HTTP filters).
How severe is CVE-2020-35470?: CVE-2020-35470 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-35470 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-35470?: CVE-2020-35470 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-35470?: 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-2020-35470 published?: CVE-2020-35470 was published on 2020-12-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

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