CVE-2024-23326

highpriority · track · 33EPSS 0.004 · 30 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.36% (30th) EPSS

CVSS 8.2 · high

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.2

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.9–8.2

v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 4.2

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · ENISA EU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · security-advisories@github.comexploitability 2.2 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444USprimaryCWE-391US

affected products (12)

Products and version ranges known to be affected.

envoyproxy envoy≤ 1.29.0, ≤ 1.29.4enisa_euvdEU
envoyproxy envoy≤ ≤ 1.27.5enisa_euvdEU
envoyproxy envoy≤ 1.13.0, ≤ 1.30.1enisa_euvdEU
envoyproxy envoy≤ 1.28.0, ≤ 1.28.3enisa_euvdEU
envoyproxy envoy< 1.27.6nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy1.28.0 → 1.28.4nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy1.29.0 → 1.29.5nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy1.30.0 → 1.30.2nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
Bitnami envoy< 1.27.6osvUSpkg:bitnami/envoy
Bitnami envoy1.28.0 → 1.28.4osvUSpkg:bitnami/envoy
Bitnami envoy1.29.0 → 1.29.5osvUSpkg:bitnami/envoy
Bitnami envoy1.30.0 → 1.30.2osvUSpkg:bitnami/envoy

advisories (1)

Vendor and ecosystem advisories describing this.

BIT-envoy-2024-23326Envoy incorrectly accepts HTTP 200 response for entering upgrade mode2024-06-06vendor · osvUS
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.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2024-06-04modified 2026-06-17

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+548 more

references (4)

External citations — patches, advisories, analysis.

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