High severity · published Jun 8, 2026
CVE-2026-49975
Apache HTTP Server: mod_http2 denial of service
7.5
CVSS
33%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)33.0% · higher than 98% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HS
HTTP Server · Apache
2.4.17 through 2.4.67 · source: vendor, NVD
DL
Debian Linux · Debian
11.0 · source: NVD
JC
JBoss Core Services for RHEL 8 · Red Hat
All versions, or not specified · source: CISA
JC
JBoss Core Services on RHEL 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.8 Telecommunications Update Service · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-49975
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-49975
Vendor Advisory
https://httpd.apache.org/security/vulnerabilities_24.html
Mailing List
http://www.openwall.com/lists/oss-security/2026/06/03/3
Mailing List
http://www.openwall.com/lists/oss-security/2026/06/08/16
Mailing List
https://lists.debian.org/debian-lts-announce/2026/06/msg00009.html
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:25042
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:25057
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