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Vulnerability details: VCID-kv7f-t14h-2bfv
Vulnerability ID VCID-kv7f-t14h-2bfv
Aliases CVE-2016-1546
Summary By manipulating the flow control windows on streams, a client was able to block server threads for long times, causing starvation of worker threads. Connections could still be opened, but no streams where processed for these. This issue affected HTTP/2 support in 2.4.17 and 2.4.18.
Status Published
Exploitability 0.5
Weighted Severity 5.3
Risk 2.6
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-399 Resource Management Errors
System Score Found at
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
epss 0.41505 https://api.first.org/data/v1/epss?cve=CVE-2016-1546
apache_httpd low https://httpd.apache.org/security/json/CVE-2016-1546.json
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2016-1546
cvssv3 5.9 https://nvd.nist.gov/vuln/detail/CVE-2016-1546
Reference id Reference type URL
http://httpd.apache.org/security/vulnerabilities_24.html
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-1546.json
https://api.first.org/data/v1/epss?cve=CVE-2016-1546
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-1546
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rb14daf9cc4e28d18cdc15d6a6ca74e565672fabf7ad89541071d008b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E
https://security.netapp.com/advisory/ntap-20180601-0001/
http://svn.apache.org/viewvc?view=revision&revision=1733727
http://www.apache.org/dist/httpd/CHANGES_2.4
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
http://www.securityfocus.com/bid/92331
1336350 https://bugzilla.redhat.com/show_bug.cgi?id=1336350
cpe:2.3:a:apache:http_server:2.4.17:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:apache:http_server:2.4.17:*:*:*:*:*:*:*
cpe:2.3:a:apache:http_server:2.4.18:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:apache:http_server:2.4.18:*:*:*:*:*:*:*
CVE-2016-1546 https://httpd.apache.org/security/json/CVE-2016-1546.json
CVE-2016-1546 https://nvd.nist.gov/vuln/detail/CVE-2016-1546
GLSA-201610-02 https://security.gentoo.org/glsa/201610-02
RHSA-2017:1161 https://access.redhat.com/errata/RHSA-2017:1161
No exploits are available.
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2016-1546
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2016-1546
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.97382
EPSS Score 0.41505
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:36:20.118335+00:00 Apache HTTPD Importer Import https://httpd.apache.org/security/json/CVE-2016-1546.json 38.0.0