Is CVE-2023-35944 actively exploited?

CVE-2023-35944 has no public evidence of in-the-wild exploitation as of 2024-11-21.

What is the CVSS score for CVE-2023-35944?

CVE-2023-35944 has a CVSS score of 8.2 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

How do I patch CVE-2023-35944?

Patch guidance is available from envoyproxy security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2023-35944.

Fix CVE-2023-35944 - HIGH envoyproxy envoy

Q: Which products are affected by CVE-2023-35944?

4 products: envoyproxy envoy, envoyproxy envoy, envoyproxy envoy, envoyproxy envoy.

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Envoy allows mixed-case schemes in HTTP/2, however, some internal scheme checks are case-sensitive. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, this can lead to the rejection of requests with mixed-case schemes such as `htTp` or `htTps`, or the bypassing of some requests such as `https` in unencrypted connections. With a fix in versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, Envoy will now lowercase scheme values by default, and change the internal scheme checks that were case-sensitive to be case-insensitive. There are no known workarounds for this issue.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: low
Availability: none
Weaknesses: CWE-20 · Improper Input Validation CWE-444

Metadata

Primary Vendor: ENVOYPROXY
Published: 7/25/2023
Last Modified: 11/21/2024
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

envoyproxy : envoyenvoyproxy : envoyenvoyproxy : envoyenvoyproxy : envoy

Remediation Guidance

Executive Summary

Cite this page

CVE-2023-35944. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2023-35944

View on NIST NVD

CVE-2023-35944 vulnerability