How severe is CVE-2026-50572?

CVE-2026-50572 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-50572 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-50572?

CVE-2026-50572 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-50572?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-50572 published?

CVE-2026-50572 was published on 2026-09-21 and last updated on 2026-10-05.

CVE-2026-50572

CVE-2026-50572 is a medium-severity vulnerability in Envoyproxy Envoy with a CVSS 3.x base score of 5.9. 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-416.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Envoyproxy Envoy
Published: 2026-09-21
Last modified: 2026-10-05

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's HTTP external-authorization client can retain a stale request callback after a request is rejected. When RawHttpClientImpl::onSuccess later processes the authorization response, it can invoke callbacks_ after the callback owner has been destroyed, causing a use-after-free and process crash under production traffic. The relevant scope boundary is that the vulnerable path uses the HTTP ext_authz client; the advisory does not establish the same trigger for unrelated filters. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

Frequently asked questions

What is CVE-2026-50572?: Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's HTTP external-authorization client can retain a stale request callback after a request is rejected. When RawHttpClientImpl::onSuccess later processes the authorization response, it can invoke callbacks_ after the callback owner has been destroyed, causing a use-after-free and process crash under production traffic. The relevant scope boundary is that the vulnerable path uses the HTTP ext_authz client; the advisory does not establish the same trigger for unrelated filters. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
How severe is CVE-2026-50572?: CVE-2026-50572 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-50572 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-50572?: CVE-2026-50572 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-50572?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-50572 published?: CVE-2026-50572 was published on 2026-09-21 and last updated on 2026-10-05.

References

Affected products (1)

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

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