Skip to content
Fencer Vulns
medium 5.9

CVE-2024-23326 json

Envoy incorrectly accepts HTTP 200 response for entering upgrade mode

published 2024-06-04 2 y ago modified 2026-09-08 2 mo ago also BIT-envoy-2024-23326 , EUVD-2024-20841 , GHSA-vcf8-7238-v74c

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rfc/rfc7230#section-6.7 a server sends 101 when switching protocols. Envoy incorrectly accepts a 200 response from a server when requesting a protocol upgrade, but 200 does not indicate protocol switch. This opens up the possibility of request smuggling through Envoy if the server can be tricked into adding the upgrade header to the response.

Patch / fix

  • bitnami envoy 1.27.6, 1.28.4, 1.29.5, 1.30.2
  • envoyproxy envoy 1.27.6, 1.28.4, 1.29.5, 1.30.2

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-2024-23326 updated cvss 5.4

envoy: Envoy incorrectly accepts HTTP 200 response for entering upgrade mode

  • Red Hat OpenShift Service Mesh 2 servicemesh-proxy, servicemesh-proxy-wasm
    affected: no fix planned “Will not fix”
  • Red Hat RHOSSM 2.5 for RHEL 8 openshift-service-mesh/pilot-rhel8 2.5.5-4, openshift-service-mesh/grafana-rhel8 2.5.5-3, openshift-service-mesh/kiali-rhel8 1.73.15-3, openshift-service-mesh/proxyv2-rhel8 2.5.5-6, openshift-service-mesh/istio-cni-rhel8 2.5.5-4, openshift-service-mesh/ratelimit-rhel8 2.5.5-3, +2 more
    fixed: vendor fix RHSA-2024:7725

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
2 y ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
OSV 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami envoy
<1.27.6
>=1.28.0, <1.28.4
>=1.29.0, <1.29.5
>=1.30.0, <1.30.2
1.27.6
1.28.4
1.29.5
1.30.2

Affected products

  • envoyproxy envoy

Classification

Weakness
  • CWE-391 DEPRECATED: Unchecked Error Condition
  • CWE-444 Inconsistent Interpretation of HTTP Requests

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.