Is CVE-2026-48743 actively exploited?

No active exploitation of CVE-2026-48743 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-48743 be exploited remotely?

Yes. CVE-2026-48743 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-48743?

CVE-2026-48743 has a CVSS score of 7.5 (HIGH).

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HIGH

CVE-2026-48743

CWE-444Published: June 26, 2026· Updated: Jun 29, 2026

7.5

CVSS v3.1

EPSS:0.30%probability of exploitation in 30 daysPercentile:22.0th

Official Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.

NVD Source

Technical Analysis

CVE-2026-48743 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.