Maple Labs

CVE search · CVE-2026-73548

CVE-2026-73548

high 7.5

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 forwards data for a configured non-WebSocket HTTP upgrade before the upstream accepts the upgrade. An unauthenticated HTTP/2 client can place a complete HTTP/1.1 request in extended CONNECT data; Envoy downgrades the request, writes the data unframed to a keep-alive HTTP/1.1 upstream, and returns the socket to the shared pool while the smuggled response remains queued. A different downstream client can then receive the attacker's response. The relevant scope boundary is that webSocket upgrades, plain CONNECT, disabled backend keep-alive, per-downstream pools, and max_requests_per_connection set to 1 are not affected by the demonstrated path. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

Open in the NVD CVE.org JSON

Details

Status
Analyzed
Published
Last changed
Source
security-advisories@github.com
Weakness
CWE-444

Severity

VersionScoreVectorSource
CVSS 3.1 high 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N security-advisories@github.comSecondary

Affected products

Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.

References