CVE-2023-35944

mediumpriority · track · 21EPSS 0.007 · 53 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.70% (53rd) EPSS
CVSS 5.3 · medium
Is it mine?
21 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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.

01

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 · 4.9–8.2

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v3.18.2highAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:Nsecondary · FSTEC (BDU) RU
v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:Nsecondary · ENISA EU
v3.18.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:Nsecondary · security-advisories@github.comexploitability 3.9 · impact 4.2
v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

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

Exploitation: poc · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444USprimaryCWE-20USCWE-20US
04

affected products (21)

Products and version ranges known to be affected.

showing 20 of 21
05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-2058Red Hat OpenShift Service Mesh und Service Mesh Containers: Mehrere SchwachstellenDeutsch2023-08-13csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat OpenShift Service Mesh und Service Mesh Containers, sowie Red Hat Enterprise Linux ausnutzen, um einen Denial of Service Zustand herbeizuführen, Dateien zu manipulieren, Sicherheitsvorkehrungen zu umgehen oder Informationen offenzulegen.

  • BIT-envoy-2023-35944Envoy vulnerable to incorrect handling of HTTP requests and responses with mixed case schemes2024-03-06vendor · osvUS

    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.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundnvdNVDCVE.orgMITRE
published 2023-07-25modified 2026-06-17
09

references (6)

External citations — patches, advisories, analysis.

scry

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