Cyber Resilience

CVE-2026-49975

Apache Http Server 2.4.17 – 2.4.68

Public PoC
Published
08 June 2026
Modified
05 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.28 98th percentile
Risk Priority 72 floored blend · peak EPSS

Summary

CVE-2026-49975 is a high-severity Memory Allocation with Excessive Size Value (CWE-789) vulnerability in Apache Http Server. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Memory Allocation with Excessive Size Value vulnerability in Apache HTTP Server's mod_http leads to denial of service via malicious HTTP requests. This issue affects Apache HTTP Server: from 2.4.17 through 2.4.67.

CWE(s)
CWE-789CWE-409

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-53020Same product: Apache Http Server
CVE-2023-45802Same product: Apache Http Server
CVE-2025-3891Same product: Apache Http Server
CVE-2023-24998Same product: Debian Debian Linux
CVE-2026-44186Same product: Apache Http Server
CVE-2023-27522Same product: Apache Http Server
CVE-2023-31122Same product: Apache Http Server
CVE-2024-52316Same product: Debian Debian Linux
CVE-2026-53917Same vendor: Apache
CVE-2026-53916Same vendor: Apache

Affected Assets

apache
http server
2.4.17 — 2.4.68
debian
debian linux
11.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly rejects or bounds untrusted size values before any allocation occurs.

SC-5 Denial-of-service Protection partial match

DoS protection limits the resource-exhaustion impact when a decompression bomb is processed.

SC-6 Resource Availability partial match

Resource quotas and priority allocation limit the system-wide impact of an oversized request.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent coding flaws that trust unvalidated size values for allocations.

DE.CM-09 partial match
prevents

Runtime monitoring of compute resources can detect exhaustion caused by decompression bombs.

PR.IR-04 partial match
prevents

Capacity planning and monitoring directly limits the availability impact of data-amplification attacks.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect and block excessive allocation flaws before deployment.

A.8.14 Redundancy of information processing facilities partial match
mitigates

Redundancy helps availability but does not address the root cause of the weakness.

A.8.16 Monitoring activities partial match
finds

Monitoring can detect anomalous resource usage but does not prevent the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes input validation and size checks that prevent unbounded allocations.

A.8.26 Application security requirements partial match
prevents

Application security requirements mandate bounds checking on size parameters to avoid excessive memory allocation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles require resource-limit enforcement that mitigates uncontrolled memory requests.

References