Is CVE-2026-48743 in the CISA KEV catalog?

No. CVE-2026-48743 is not currently on the CISA Known Exploited Vulnerabilities list.

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

CVE-2026-48743 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-48743?

CVE-2026-48743 has an EPSS score of 0.30% (22th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-48743

HIGH

7.5

CVSS v3

NVD

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.

CWE-444

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityLow

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N

Exploit Intelligence

0.30%probability of exploitation in 30 days

22ndpercentile

Low risk: more likely to be exploited than 22% of all known CVEs.

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-26.