CVE-2024-23323Network attack vector

Service degradation via per-request regex compilation

Published Feb 9, 2024 · Updated Aug 1, 2024

Resource exhaustion in Envoy allows remote attackers to degrade service via requests matching configured regex URI-template routes. The URI-template matcher compiles its regular-expression object anew for every request instead of caching it, repeating the work across matching routes. Exposure requires multiple routes using this matcher; affected requests consume excessive CPU and increase latency without reported data disclosure or modification.

CVSS severity4.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Envoy allows remote attackers to degrade service via requests matching configured regex URI-template routes. The URI-template matcher compiles its regular-expression object anew for every request instead of caching it, repeating the work across matching routes. Exposure requires multiple routes using this matcher; affected requests consume excessive CPU and increase latency without reported data disclosure or modification.

The record

CVE
CVE-2024-23323
Published
Feb 9, 2024
Updated
Aug 1, 2024
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-1176, CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 1.26.7
  2. Affected versionversion=>= 1.27.0, < 1.27.3
  3. Affected versionversion=>= 1.28.0, < 1.28.1
  4. Affected versionversion=>= 1.29.0, < 1.29.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Envoy Proxy · Envoyversion=< 1.26.7; version=>= 1.27.0, < 1.27.3; version=>= 1.28.0, < 1.28.1; version=>= 1.29.0, < 1.29.1

Published CVSS scores

4.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-1176Inefficient CPU Computation
CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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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