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01 Record

CVE-2026-49975

Apache HTTP Server: mod_http2 denial of service

HighPUBLISHEDCNA: apache
CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
View raw JSON

02 Description

Apache HTTP Server: mod_http2 denial of service

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
32.95% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 98.3% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-08-19.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-06-08 15:26Z4 MO AGO
Last updated
2026-08-19 12:05Z2 MO AGO
Reserved
2026-06-02
Assigning CNA
apache
Record state
PUBLISHED
Severity
High (CVSS 7.5)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
  • CWE-789Memory Allocation with Excessive Size ValueVariant
  • CWE-409Improper Handling of Highly Compressed Data (Data Amplification)Base
Data version
5.2
Document digest
c01b9e3ddcb030c5d3626b9fc1d2c07ef841a3cc2104b2a1de1283298b0c19c7

05 Affected products

VendorProductVersionsPlatforms
Apache Software FoundationApache HTTP Server2.4.17 to 2.4.67—

06 References

07 Fixed in

AlmaLinux 8

  • httpd
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • httpd-devel
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • httpd-filesystem
    Fixed in 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • httpd-manual
    Fixed in 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • httpd-tools
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_http2
    Fixed in 1.15.7-10.module_el8.10.0+4190+704ad79b.6
  • mod_ldap
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_md
    Fixed in 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2
  • mod_proxy_html
    Fixed

    A version is affected if any line below covers it.

    • Affected before 1:2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 1:2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_session
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_ssl
    Fixed

    A version is affected if any line below covers it.

    • Affected before 1:2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 1:2.4.37-65.module_el8.10.0+4190+704ad79b.8

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • mod_http2
    Fixed in 2.0.26-6.el9_8.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • mod_http2
    Fixed in 2.0.29-4.el10_2.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • httpd
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • httpd-devel
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • httpd-filesystem
    Fixed in 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • httpd-manual
    Fixed in 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
  • httpd-tools
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_http2
    Fixed in 1.15.7-10.module_el8.10.0+4190+704ad79b.6
  • mod_ldap
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_md
    Fixed in 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2
  • mod_proxy_html
    Fixed

    A version is affected if any line below covers it.

    • Affected before 1:2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 1:2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_session
    Fixed

    A version is affected if any line below covers it.

    • Affected before 2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 2.4.37-65.module_el8.10.0+4190+704ad79b.8
  • mod_ssl
    Fixed

    A version is affected if any line below covers it.

    • Affected before 1:2.4.37-65.module_el8.10.0+4185+0955a0d7.8
    • Affected before 1:2.4.37-65.module_el8.10.0+4190+704ad79b.8

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • mod_http2
    Fixed in 2.0.26-6.el9_8.1

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • mod_http2
    Fixed in 2.0.29-4.el10_2.1

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • apache2
    Fixed in 2.4.67-1~deb12u3

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • apache2
    Fixed in 2.4.67-1~deb13u3

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • apache2
    Fixed in 2.4.67-2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • apache2
    Fixed in 2.4.52-1ubuntu4.21
  • nginx
    Fixed in 1.18.0-6ubuntu14.15

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • apache2
    Fixed in 2.4.58-1ubuntu8.13
  • nginx
    Fixed in 1.24.0-2ubuntu7.12

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • apache2
    Fixed in 2.4.64-1ubuntu3.5
  • nginx
    Fixed in 1.28.0-6ubuntu1.7

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • apache2
    Fixed in 2.4.66-2ubuntu2.2
  • nginx
    Fixed in 1.28.3-2ubuntu1.5

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • nginx
    Fixed in 1.4.6-1ubuntu3.9+esm8
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • apache2
    Fixed in 2.4.18-2ubuntu3.17+esm19
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro
  • nginx
    Fixed in 1.10.3-0ubuntu0.16.04.5+esm9
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • apache2
    Fixed in 2.4.29-1ubuntu4.27+esm10
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • nginx
    Fixed in 1.14.0-0ubuntu1.11+esm4
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • apache2
    Fixed in 2.4.41-4ubuntu3.23+esm5
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • nginx
    Fixed in 1.18.0-0ubuntu1.7+esm3
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.