How severe is CVE-2023-35941?

CVE-2023-35941 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2023-35941 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-35941?

CVE-2023-35941 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-35941?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-35941 published?

CVE-2023-35941 was published on 2023-07-25 and last updated on 2026-06-17.

CVE-2023-35941

CVE-2023-35941 is a high-severity vulnerability in Envoyproxy Envoy with a CVSS 3.x base score of 8.6. 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-116.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-116
Affected product: Envoyproxy Envoy
Published: 2023-07-25
Last modified: 2026-06-17

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, a malicious client is able to construct credentials with permanent validity in some specific scenarios. This is caused by the some rare scenarios in which HMAC payload can be always valid in OAuth2 filter's check. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, avoid wildcards/prefix domain wildcards in the host's domain configuration.

Frequently asked questions

What is CVE-2023-35941?: Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, a malicious client is able to construct credentials with permanent validity in some specific scenarios. This is caused by the some rare scenarios in which HMAC payload can be always valid in OAuth2 filter's check. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, avoid wildcards/prefix domain wildcards in the host's domain configuration.
How severe is CVE-2023-35941?: CVE-2023-35941 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2023-35941 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-35941?: CVE-2023-35941 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-35941?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-35941 published?: CVE-2023-35941 was published on 2023-07-25 and last updated on 2026-06-17.

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-7mhv-gr67-hq55

Affected products (1)

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

More vulnerabilities in Envoyproxy Envoy

CVE-2022-29226 — Critical (CVSS 10.0): Envoy is a cloud-native high-performance proxy. In versions prior to 1.22.1 the OAuth filter implementation does not…
CVE-2019-18802 — Critical (CVSS 9.8): An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with…
CVE-2019-18801 — Critical (CVSS 9.8): An issue was discovered in Envoy 1.12.0. An untrusted remote client may send HTTP/2 requests that write to the heap…
CVE-2020-35470 — High (CVSS 8.8): Envoy before 1.16.1 logs an incorrect downstream address because it considers only the directly connected peer, not the…
CVE-2024-23324 — High (CVSS 8.6): Envoy is a high-performance edge/middle/service proxy. External authentication can be bypassed by downstream…
CVE-2021-39206 — High (CVSS 8.6): Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, contains two authorization…

All CVEs affecting Envoyproxy Envoy →

Other CWE-116 vulnerabilities

CVE-2025-55730 — Critical (CVSS 10.0): XWiki Remote Macros provides XWiki rendering macros that are useful when migrating content from Confluence. Starting in…
CVE-2025-55729 — Critical (CVSS 10.0): XWiki Remote Macros provides XWiki rendering macros that are useful when migrating content from Confluence. Starting in…
CVE-2023-47143 — Critical (CVSS 10.0): IBM Tivoli Application Dependency Discovery Manager 7.3.0.0 through 7.3.0.10 is vulnerable to HTTP header injection,…
CVE-2023-26472 — Critical (CVSS 9.9): XWiki Platform is a generic wiki platform. Starting in version 6.2-milestone-1, one can execute any wiki content with…
CVE-2022-41934 — Critical (CVSS 9.9): XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user with…
CVE-2022-36100 — Critical (CVSS 9.9): XWiki Platform Applications Tag and XWiki Platform Tag UI are tag applications for XWiki, a generic wiki platform.…

Browse all CWE-116 vulnerabilities →