CVE-2024-27316Network attack vector

Unauthenticated service interruption via unbounded header buffering

Published Apr 4, 2024 · Updated Nov 4, 2025

HTTP/2 handling in Apache HTTP Server 2.4.17 through 2.4.58 allows remote attackers to exhaust memory via endless header frames. After the header limit is exceeded, the request path keeps buffering incoming CONTINUATION frames in nghttp2 while preparing an HTTP 413 response. An unauthenticated client with HTTP/2 access can keep a request open until the server runs out of memory and service is interrupted.

CVSS severity7.5
High
EPSS probability91.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP/2 handling in Apache HTTP Server 2.4.17 through 2.4.58 allows remote attackers to exhaust memory via endless header frames. After the header limit is exceeded, the request path keeps buffering incoming CONTINUATION frames in nghttp2 while preparing an HTTP 413 response. An unauthenticated client with HTTP/2 access can keep a request open until the server runs out of memory and service is interrupted.

The record

CVE
CVE-2024-27316
Published
Apr 4, 2024
Updated
Nov 4, 2025
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-770, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record 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=2.4.17 <=2.4.58

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=2.4.17 <=2.4.58

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS: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-770Allocation of Resources Without Limits or Throttling
T1499.003Endpoint Denial of Service: Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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