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Fencer Vulns
high 7.5

CVE-2026-49975 in the critical feed json

Apache HTTP Server: mod_http2 denial of service

published 2026-06-08 5 mo ago modified 2026-09-08 2 mo ago also BIT-apache-2026-49975 , EUVD-2026-35105

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
33.0%
EPSS 33.0% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami apache 2.4.68
  • Red Hat JBoss Core Services for RHEL 8 0:2.0.29-10.el8jbcs, 0:2.4.62-13.el8jbcs
  • Red Hat JBoss Core Services on RHEL 7 0:2.0.29-10.el7jbcs, 0:2.4.62-13.el7jbcs
  • Red Hat Red Hat Enterprise Linux 10 0:2.0.29-4.el10_2.1
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:2.0.29-2.el10_0.2
  • Red Hat Red Hat Enterprise Linux 8 8100020260608081321.489197e6
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020260702193120.522a0ee4
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020260702193120.522a0ee4
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 8060020260702195216.ad008a3a
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 8060020260702195216.ad008a3a
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 8080020260702200145.63b34585
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 8080020260702200145.63b34585
  • Red Hat Red Hat Enterprise Linux 9 0:2.0.26-6.el9_8.1
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:1.15.19-4.el9_2.8
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:2.0.26-2.el9_4.3
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:2.0.26-4.el9_6.2
  • Red Hat Red Hat JBoss Core Services 2.4.62.SP4 httpd24-httpd, httpd24-mod_http2
  • Red Hat Red Hat Hardened Images 2.4.68-1.hum1
  • Red Hat Red Hat OpenShift Service Mesh 2.6 1781604724
  • apache2 Debian 12 2.4.67-1~deb12u3
  • apache2 Debian 13 2.4.67-1~deb13u3
  • apache2 Debian 14 2.4.67-2

debian advisories DEBIAN-CVE-2026-49975

  • nginx Ubuntu 22.04 LTS 1.18.0-6ubuntu14.15
  • nginx Ubuntu 24.04 LTS 1.24.0-2ubuntu7.12
  • nginx Ubuntu 25.10 1.28.0-6ubuntu1.7
  • nginx Ubuntu 26.04 LTS 1.28.3-2ubuntu1.5
  • apache2 Ubuntu 22.04 LTS 2.4.52-1ubuntu4.21
  • apache2 Ubuntu 24.04 LTS 2.4.58-1ubuntu8.13
  • apache2 Ubuntu 25.10 2.4.64-1ubuntu3.5
  • apache2 Ubuntu 26.04 LTS 2.4.66-2ubuntu2.2

ubuntu advisories UBUNTU-CVE-2026-49975

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • jbcs-httpd24-httpd jboss core services 1 2.4.62-13.el7jbcs
  • jbcs-httpd24-httpd jboss core services 1 2.4.62-13.el8jbcs
  • jbcs-httpd24-mod_md jboss core services 1 1:2.4.28-16.el7jbcs
  • jbcs-httpd24-mod_md jboss core services 1 1:2.4.28-16.el8jbcs
  • jbcs-httpd24-mod_ssl jboss core services 1 1:2.4.62-13.el7jbcs
  • jbcs-httpd24-mod_ssl jboss core services 1 1:2.4.62-13.el8jbcs
  • jbcs-httpd24-nghttp2 jboss core services 1 1.64.0-3.el7jbcs
  • jbcs-httpd24-nghttp2 jboss core services 1 1.64.0-3.el8jbcs

red hat advisories RHSA-2026:55992RHSA-2026:55930RHSA-2026:50538RHSA-2026:50572RHSA-2026:36846RHSA-2026:36831

  • apache2 SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2-event SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2-utils SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2-manual SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2-worker SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2-prefork SLES for SAP applications 16.0, SLES 16.0 2.4.66-160000.3.1
  • apache2 SLE Module for Basesystem 15 SP7 2.4.66-150700.4.23.1
  • apache2-event SLE Module for Package Hub 15 SP7 2.4.66-150700.4.23.1

suse advisories SUSE-SU-2026:22564-1SUSE-SU-2026:2759-1SUSE-SU-2026:2735-1SUSE-SU-2026:2717-1SUSE-SU-2026:2686-1

  • apache2 openSUSE Leap 16.0 2.4.66-160000.3.1
  • apache2-event openSUSE Leap 16.0 2.4.66-160000.3.1
  • apache2-utils openSUSE Leap 16.0 2.4.66-160000.3.1
  • apache2-manual openSUSE Leap 16.0 2.4.66-160000.3.1
  • apache2-worker openSUSE Leap 16.0 2.4.66-160000.3.1
  • apache2-prefork openSUSE Leap 16.0 2.4.66-160000.3.1

opensuse advisories openSUSE-SU-2026:21235-1

  • mod_http2 AlmaLinux 10 2.0.29-4.el10_2.1
  • mod_http2 AlmaLinux 9 2.0.26-6.el9_8.1
  • httpd AlmaLinux 8 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • httpd AlmaLinux 8 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_md AlmaLinux 8 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2
  • mod_ssl AlmaLinux 8 1:2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • mod_ssl AlmaLinux 8 1:2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_ldap AlmaLinux 8 2.4.37-65.module_el8.10.0+4185+0955a0d7.8

almalinux advisories ALSA-2026:25225ALSA-2026:25057ALSA-2026:25090

  • mod_http2 Rocky Linux 10 2.0.29-4.el10_2.1
  • mod_http2 Rocky Linux 9 2.0.26-6.el9_8.1
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40045+6ce8579b.6
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40197+0231e209.8
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40053+5a18018e.7
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+1840+b070a976.1
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+1842+4a9649e8.2
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+2061+8d03fdec.5

rocky linux advisories RLSA-2026:25225RLSA-2026:25057RLSA-2026:25090

  • nginx Alpine 3.21 1.26.3-r1
  • nginx Alpine 3.23, Alpine 3.22 1.28.3-r3
  • nginx Alpine 3.24 1.30.1-r0
  • apache2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 2.4.68-r0

alpine advisories ALPINE-CVE-2026-49975

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • httpd Azure Linux 3.0 2.4.68-1
  • nginx Azure Linux 3.0 1.28.3-5

azure linux advisories AZL-89550AZL-89760

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-49975 updated cvss 7.5

httpd: httpd: HTTP/2 Remote Denial of Service via compression bomb and Slowloris-style attack

  • Red Hat Enterprise Linux AppStream (v. 8) mod_md 2.0.8-8.module+el8.10.0+23815+1b5e1c66.2, httpd 2.4.37-65.module+el8.10.0+24281+ea10630c.8, mod_ssl 2.4.37-65.module+el8.10.0+24281+ea10630c.8, mod_ldap 2.4.37-65.module+el8.10.0+24281+ea10630c.8, mod_http2 1.15.7-10.module+el8.10.0+24368+ad388a0c.6, httpd-tools 2.4.37-65.module+el8.10.0+24281+ea10630c.8, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:25090
  • Red Hat Enterprise Linux AppStream (v. 9) mod_http2 2.0.26-6.el9_8.1
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:25057
  • Red Hat Enterprise Linux AppStream (v. 10) mod_http2 2.0.29-4.el10_2.1
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:25225
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) mod_md 2.0.8-8.module+el8.4.0+23842+00253415.1, httpd 2.4.37-39.module+el8.4.0+24495+1afced82.12, mod_http2 1.15.7-3.module+el8.4.0+24495+1afced82.5, mod_ssl 2.4.37-39.module+el8.4.0+24495+1afced82.12, mod_ldap 2.4.37-39.module+el8.4.0+24495+1afced82.12, httpd-tools 2.4.37-39.module+el8.4.0+24495+1afced82.12, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36846
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) mod_md 2.0.8-8.module+el8.6.0+23843+c27a5dc4.1, httpd 2.4.37-47.module+el8.6.0+24496+af8fe930.13, mod_http2 1.15.7-5.module+el8.6.0+24496+af8fe930.5, mod_ssl 2.4.37-47.module+el8.6.0+24496+af8fe930.13, mod_ldap 2.4.37-47.module+el8.6.0+24496+af8fe930.13, httpd-tools 2.4.37-47.module+el8.6.0+24496+af8fe930.13, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36831
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) mod_md 2.0.8-8.module+el8.8.0+23840+d7e7db80.1, httpd 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, mod_http2 1.15.7-8.module+el8.8.0+24497+e470c0e2.7, mod_ssl 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, mod_ldap 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, httpd-tools 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36373
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) mod_http2 1.15.19-4.el9_2.8
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:55930
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) mod_http2 2.0.26-2.el9_4.3
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:55992
show 12 more
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) mod_http2 2.0.29-2.el10_0.2
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:50538
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) mod_http2 2.0.26-4.el9_6.2
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:50572
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) mod_md 2.0.8-8.module+el8.4.0+23842+00253415.1, httpd 2.4.37-39.module+el8.4.0+24495+1afced82.12, mod_http2 1.15.7-3.module+el8.4.0+24495+1afced82.5, mod_ssl 2.4.37-39.module+el8.4.0+24495+1afced82.12, mod_ldap 2.4.37-39.module+el8.4.0+24495+1afced82.12, httpd-tools 2.4.37-39.module+el8.4.0+24495+1afced82.12, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36846
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) mod_md 2.0.8-8.module+el8.6.0+23843+c27a5dc4.1, httpd 2.4.37-47.module+el8.6.0+24496+af8fe930.13, mod_http2 1.15.7-5.module+el8.6.0+24496+af8fe930.5, mod_ssl 2.4.37-47.module+el8.6.0+24496+af8fe930.13, mod_ldap 2.4.37-47.module+el8.6.0+24496+af8fe930.13, httpd-tools 2.4.37-47.module+el8.6.0+24496+af8fe930.13, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36831
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) mod_md 2.0.8-8.module+el8.8.0+23840+d7e7db80.1, httpd 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, mod_http2 1.15.7-8.module+el8.8.0+24497+e470c0e2.7, mod_ssl 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, mod_ldap 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, httpd-tools 2.4.37-56.module+el8.8.0+24497+e470c0e2.12, +4 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:36373
  • Red Hat Hardened Images httpd 2.4.68-1.hum1, httpd-core 2.4.68-1.hum1, httpd-tools 2.4.68-1.hum1, httpd-manual 2.4.68-1.hum1, httpd-filesystem 2.4.68-1.hum1
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:25042
  • Red Hat JBoss Core Services 2.4.62.SP4
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:27201
  • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-httpd 2.4.62-13.el7jbcs, jbcs-httpd24-mod_ssl 2.4.62-13.el7jbcs, jbcs-httpd24-mod_ldap 2.4.62-13.el7jbcs, jbcs-httpd24-mod_http2 2.0.29-10.el7jbcs, jbcs-httpd24-httpd-tools 2.4.62-13.el7jbcs, jbcs-httpd24-mod_session 2.4.62-13.el7jbcs, +3 more Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-httpd 2.4.62-13.el8jbcs, jbcs-httpd24-mod_ssl 2.4.62-13.el8jbcs, jbcs-httpd24-mod_ldap 2.4.62-13.el8jbcs, jbcs-httpd24-mod_http2 2.0.29-10.el8jbcs, jbcs-httpd24-httpd-tools 2.4.62-13.el8jbcs, jbcs-httpd24-mod_session 2.4.62-13.el8jbcs, +3 more
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:27200
  • Red Hat OpenShift Service Mesh 2.6 openshift-service-mesh/proxyv2-rhel9 1781604724
    fixed: vendor fix “See the security bulletin for a detailed mitigation procedure.” RHSA-2026:27114
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) mod_http2-debuginfo 1.15.19-4.el9_2.8, mod_http2-debugsource 1.15.19-4.el9_2.8 Red Hat Enterprise Linux AppStream E4S (v.9.4) mod_http2-debuginfo 2.0.26-2.el9_4.3, mod_http2-debugsource 2.0.26-2.el9_4.3 Red Hat Enterprise Linux AppStream EUS (v. 10.0) mod_http2-debuginfo 2.0.29-2.el10_0.2, mod_http2-debugsource 2.0.29-2.el10_0.2 Red Hat Enterprise Linux AppStream EUS (v.9.6) mod_http2-debuginfo 2.0.26-4.el9_6.2, mod_http2-debugsource 2.0.26-4.el9_6.2 Red Hat Hardened Images mod_lua 2.4.68-1.hum1, mod_ssl 2.4.68-1.hum1, mod_ldap 2.4.68-1.hum1, mod_session 2.4.68-1.hum1, mod_proxy_html 2.4.68-1.hum1
    not affected: vulnerable code not present
  • Red Hat JBoss Core Services jbcs-httpd24-apr, jbcs-httpd24-curl, jbcs-httpd24-dist, jbcs-httpd24-brotli, jbcs-httpd24-mod_jk, jbcs-httpd24-mod_md, +27 more
    not affected: component not present
  • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-mod_md 2.4.28-16.el7jbcs, jbcs-httpd24-nghttp2 1.64.0-3.el7jbcs, jbcs-httpd24-mod_security 2.9.6-16.el7jbcs, jbcs-httpd24-mod_jk 1.2.50-14.redhat_1.el7jbcs, jbcs-httpd24-mod_proxy_cluster 1.3.22-9.el7jbcs, jbcs-httpd24-mod_jk-ap24 1.2.50-14.redhat_1.el7jbcs Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-mod_md 2.4.28-16.el8jbcs, jbcs-httpd24-nghttp2 1.64.0-3.el8jbcs, jbcs-httpd24-mod_security 2.9.6-16.el8jbcs, jbcs-httpd24-mod_jk 1.2.50-14.redhat_1.el8jbcs, jbcs-httpd24-mod_proxy_cluster 1.3.22-9.el8jbcs, jbcs-httpd24-mod_jk-ap24 1.2.50-14.redhat_1.el8jbcs Red Hat JBoss Web Server 5 jbcs-httpd24-apr, jbcs-httpd24-openssl Red Hat OpenShift Service Mesh 2.6 openshift-service-mesh/istio-must-gather-rhel9 1781579930
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

32.95% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/EQSTLab/CVE-2026-49975 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami apache
>=2.4.17, <2.4.68
2.4.68

Affected products

  • Apache Software Foundation Apache HTTP Server
  • Red Hat JBoss Core Services for RHEL 8
  • Red Hat JBoss Core Services on RHEL 7
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat JBoss Core Services 2.4.62.SP4
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat OpenShift Service Mesh 2.6
  • Red Hat Red Hat JBoss Core Services
  • Red Hat Red Hat JBoss Web Server 5

Classification

Weakness
  • CWE-789 Memory Allocation with Excessive Size Value
  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.