CVE-2022-39271Network attack vector

Unauthenticated DoS via HTTP/2 connection hang

Published Oct 11, 2022 · Updated Apr 23, 2025

Denial of service in Traefik Proxy before 2.8.8 and 2.9.0-rc5 allows remote attackers to hang HTTP/2 connections. The HTTP/2 server connection close path can wait forever after a subsequent fatal error, leaving the service unresponsive. No authentication or user interaction is required, and the demonstrated consequence is service interruption without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Traefik Proxy before 2.8.8 and 2.9.0-rc5 allows remote attackers to hang HTTP/2 connections. The HTTP/2 server connection close path can wait forever after a subsequent fatal error, leaving the service unresponsive. No authentication or user interaction is required, and the demonstrated consequence is service interruption without reported data disclosure or modification.

The record

CVE
CVE-2022-39271
Published
Oct 11, 2022
Updated
Apr 23, 2025
Vendor
Traefik Labs
Product
Traefik Proxy
Classifications
CWE-400, CWE-755, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=< 2.8.8
  2. Affected versionversion=>= 2.9.0-rc1, < 2.9.0-rc5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Traefik Labs · Traefik Proxyversion=< 2.8.8; version=>= 2.9.0-rc1, < 2.9.0-rc5

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-755Improper Handling of Exceptional Conditions
T1499.002Endpoint Denial of Service: Service Exhaustion

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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