CVE-2023-27487Public exploitNetwork attack vector

Authentication bypass via trusted client-supplied path header

Published Apr 4, 2023 · Updated Feb 11, 2025

Improper input validation in affected Envoy releases allows remote attackers to bypass JWT checks using a forged original-path header. Envoy fails to remove the client-supplied x-envoy-original-path header before request processing, so the JWT filter and logs trust its value instead of the actual request path. Authentication bypass requires the jwt_authn filter, while other deployments can record or forward a falsified path.

CVSS severity8.2
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in affected Envoy releases allows remote attackers to bypass JWT checks using a forged original-path header. Envoy fails to remove the client-supplied x-envoy-original-path header before request processing, so the JWT filter and logs trust its value instead of the actual request path. Authentication bypass requires the jwt_authn filter, while other deployments can record or forward a falsified path.

The record

CVE
CVE-2023-27487
Published
Apr 4, 2023
Updated
Feb 11, 2025
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 11, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.22.9
  2. Affected versionversion=>= 1.23.0, < 1.23.6
  3. Affected versionversion=>= 1.24.0, < 1.24.4
  4. Affected versionversion=>= 1.25.0, <1.25.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Envoy Proxy · Envoyversion=< 1.22.9; version=>= 1.23.0, < 1.23.6; version=>= 1.24.0, < 1.24.4; version=>= 1.25.0, <1.25.3

Published CVSS scores

8.2GitHub, Inc.CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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