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Fencer Vulns
medium 4.8

CVE-2026-47692 json

Envoy: PROXY Protocol v2 header generator emits "skipped" TLVs, causing 65 KB attacker-controlled spillover into the upstream application stream

published 2026-06-26 4 mo ago modified 2026-10-25 14 d ago also BIT-envoy-2026-47692 , EUVD-2026-39827 , GHSA-wh36-hm39-mm3r

cvss
4.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, PROXY Protocol v2 header generator emits TLVs beyond the maximum length of 65535 bytes, causing a mismatch between bytes written and the length field in the header. This can result in smuggled bytes on the upstream request. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

Patch / fix

  • bitnami envoy 1.35.13, 1.36.9, 1.37.5, 1.38.3
  • envoyproxy envoy 1.35.13, 1.36.9, 1.37.5, 1.38.3
  • istioctl openSUSE Tumbleweed 1.30.2-1.1

opensuse advisories openSUSE-SU-2026:11141-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-47692 updated cvss 4.8

envoy: Envoy: PROXY Protocol v2 header generator emits "skipped" TLVs, causing 65 KB attacker-controlled spillover into the upstream application stream

  • Red Hat OpenShift Service Mesh 2 openshift-service-mesh/proxyv2-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-proxyv2-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.8 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:L
NVD 3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
OSV 3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami envoy
>=1.34.0, <1.35.13
>=1.36.0, <1.36.9
>=1.37.0, <1.37.5
>=1.38.0, <1.38.3
1.35.13
1.36.9
1.37.5
1.38.3

Affected products

  • envoyproxy envoy

Classification

Weakness
  • CWE-130 Improper Handling of Length Parameter Inconsistency

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.