Every CVE Search/ Get API key

CVE-2016-1546

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of...

5.9 MediumFix available

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

15.9%Up 8.6 points since Feb 4, 2022
90%50%10%1%

What each source reports

NVD Score used 5.9

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
CVE-2016-1546
CVSS 3.0
5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:N/I:N/A:P
Weakness
CWE-399
Updated
2026-11-02
CVE List No score

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
CVE-2016-1546
Updated
2026-11-02
EUVDEUVD-2016-2641 No score

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
EUVD-2016-2641
Updated
2026-11-03
GitHub AdvisoriesGHSA-f6fj-787v-v59m 5.9

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of...

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
GHSA-f6fj-787v-v59m
CVSS 3.0
5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVBELL-CVE-2016-1546 5.9

CVE-2016-1546 does not affect BellSoft software

Record
BELL-CVE-2016-1546
CVSS 3.0
5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSV 5.9

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
CVE-2016-1546
CVSS 3.0
5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVDEBIAN-CVE-2016-1546 5.9

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

Record
DEBIAN-CVE-2016-1546
CVSS 3.0
5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVRHSA-2017:1161 7.5

Red Hat Security Advisory: httpd24-httpd security, bug fix, and enhancement update

Record
RHSA-2017:1161
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
apache2
Debian:12
 before 2.4.20-1
2.4.20-1
apache2
Debian:13
 before 2.4.20-1
2.4.20-1
apache2
Debian:14
 before 2.4.20-1
2.4.20-1
httpd24-httpd
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-httpd-debuginfo
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-httpd-devel
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-httpd-manual
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-httpd-tools
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-mod_ldap
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-mod_proxy_html
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 1:2.4.25-9.el6
1:2.4.25-9.el6
Show 11 moreShow less
Affected packages
PackageAffectedFixed
httpd24-mod_session
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el6
0:2.4.25-9.el6
httpd24-mod_ssl
Red Hat:rhel_software_collections:2::el6
From an advisory covering 6 CVEs
 before 1:2.4.25-9.el6
1:2.4.25-9.el6
httpd24-httpd
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-httpd-debuginfo
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-httpd-devel
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-httpd-manual
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-httpd-tools
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-mod_ldap
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-mod_proxy_html
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 1:2.4.25-9.el7
1:2.4.25-9.el7
httpd24-mod_session
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 0:2.4.25-9.el7
0:2.4.25-9.el7
httpd24-mod_ssl
Red Hat:rhel_software_collections:2::el7
From an advisory covering 6 CVEs
 before 1:2.4.25-9.el7
1:2.4.25-9.el7

History

History
RecordedChangedSources
affected, facts
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2016-1546 is a medium vulnerability (CVSS 5.9) in Apache Http Server, published July 6, 2016. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 15.9%, the 96th percentile. Fixed in apache2 2.4.20-1.

References

Show 64 moreShow less
Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open