How severe is CVE-2024-23326?

CVE-2024-23326 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2024-23326 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-23326?

CVE-2024-23326 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-23326?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2024-23326 have an EU (EUVD) identifier?

Yes. CVE-2024-23326 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-20841.

When was CVE-2024-23326 published?

CVE-2024-23326 was published on 2024-06-04 and last updated on 2026-06-17.

CVE-2024-23326

CVE-2024-23326 is a medium-severity vulnerability in Envoyproxy Envoy with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-20841
Weakness: CWE-444
Affected product: Envoyproxy Envoy
Published: 2024-06-04
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2024-23326?: 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.
How severe is CVE-2024-23326?: CVE-2024-23326 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2024-23326 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-23326?: CVE-2024-23326 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-23326?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-23326 have an EU (EUVD) identifier?: Yes. CVE-2024-23326 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-20841.
When was CVE-2024-23326 published?: CVE-2024-23326 was published on 2024-06-04 and last updated on 2026-06-17.

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-vcf8-7238-v74c

Affected products (1)

cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

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