vciy

CVE-2016-8740

INDEX BUILT · 2026-09-20

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The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict…

CVE-2016-87404 of 4 sources documented this
54

rank 54 = 27 + 19 + 1 + 7 + 0

rank@v1 · this cycle

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.79070  ·  without this subject the record ranks 27

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 7.5, from NVD  ·  without this subject the record ranks 35

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

rose on 2025-10-04  ·  without this subject the record ranks 53

How much of the world it touches

NVD CPE configurations

7 products in the CPE ranges  ·  without this subject the record ranks 47

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 54

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$2.42Mover the next 30 days, if this record is yours
Movement+$308,000on 2024-12-17, the last material move, 1 year, 8 months before this reading
Basisassumeda published average, not your estate

$2.42M = $4.99M incident cost x 0.6121449559255632 exposure x 0.7907 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.7907EPSSNOT IN KEVas of 2026-09-20
Severity7.5 HIGHreceipt
Harmunauthenticated · networkreceipt
Exploitationpublic proof-of-conceptreceipt
Defenseno fix version held
Movementsteadyreceipt
PLATEAU10Minimal movement since 2026-06-15, 83 days at 0.79, as of 2026-09-06. arc-rules@v1

Foresight · where to check next

CVE-2022-47966CVE-2022-29499VMware vCenterApache Log4j2QNAP Systems Inc.Microsoft8740

This record is one instance of CWE-20, improper input validation. The index holds 13347 prior instances of this class, 73 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signalspoke length is how much of the record matches, not how bad it is

Running Apache HTTP Server? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

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Harm, if it fires from the vector and the weakness

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Reachnetwork-reachable · no privileges required · no user interaction · low attack complexityreceipt
ImpactComplete availability lossreceipt
Scored fromCVSS v3.0 · NVD's vectorreceipt
Weakness classCWE-20 Improper Input Validation; CWE-399receipt
Published consequencesCWE-20: Availability: DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory); Confidentiality: Read Memory, Read Files or Directories…[email protected]

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

Fixed inNo fix version in held sources, as the index stood on 6 Sep 2026.
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Proof-of-concept published · 2 public repositories, 2017-10-11.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 2 public repositories2017-10-11receipt
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, NVD7.5 HIGHreceipt
Exploit probability0.7907 · top 0.42% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned byapachereceipt
Recorded changes60 · last 18 Sep 2026derived

Affected & Fixed Versions as published

Affected productApache Software Foundation Apache HTTP Serverreceipt
Published rangesapache http server 2.4.17; apache http server 2.4.18; apache http server 2.4.19; apache http server 2.4.20receipt
Show all 7 published ranges
apache http server 2.4.17
apache http server 2.4.18
apache http server 2.4.19
apache http server 2.4.20
apache http server 2.4.21
apache http server 2.4.22
apache http server 2.4.23

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request. receipt

NVD's analysis a second authority

severity
7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
weakness
CWE-20; CWE-399
affected versions
apache http server 2.4.17; apache http server 2.4.18; apache http server 2.4.19; and 4 more, listed in full below

check it yourself support.apple.com github.com securitytracker.com packetstormsecurity.com access.redhat.com access.redhat.com +14 morereceipt

Dated events

2023-03-07EPSS moved 0.73 to 0.032026-06-15EPSS moved 0.68 to 0.79

Movement the material steps

4 Feb 20220.72654
7 Mar 20230.02689 · crossed 0.10 and 0.50 · scoring model v2023.03.01
17 Dec 20240.14746 · crossed 0.10
17 Mar 20250.71553 · crossed 0.50 · scoring model v2025.03.14
19 Mar 20250.53449
20 Mar 20250.71553
27 Mar 20250.53449
28 Mar 20250.71553
29 Mar 20250.53449
30 Mar 20250.71553
1 Aug 20250.56733
4 Oct 20250.71517
1 Dec 20250.55491
4 Dec 20250.68259
1 Jan 20260.55491
4 Jan 20260.68259
1 Feb 20260.55491
4 Feb 20260.68259
1 Mar 20260.55491
4 Mar 20260.68259
15 Jun 20260.7907 · scoring model v2026.06.15
6 Sep 20260.7907
Show all 57 observations
4 Feb 20220.72654
7 Mar 20230.02689
11 Mar 20230.02655
1 Jun 20230.02675
27 Sep 20240.03742
30 Nov 20240.04673
17 Dec 20240.14746
2 Feb 20250.12656
7 Mar 20250.12076
17 Mar 20250.71553
19 Mar 20250.53449
20 Mar 20250.71553
27 Mar 20250.53449
28 Mar 20250.71553
29 Mar 20250.53449
30 Mar 20250.71553
1 May 20250.66741
4 May 20250.71553
1 Jun 20250.66741
4 Jun 20250.71553
1 Jul 20250.66741
4 Jul 20250.71553
30 Jul 20250.62627
1 Aug 20250.56733
4 Aug 20250.62627
1 Sep 20250.56733
4 Sep 20250.62627
20 Sep 20250.62582
1 Oct 20250.65313
4 Oct 20250.71517
6 Oct 20250.7178
27 Oct 20250.62913
28 Oct 20250.7178
1 Nov 20250.65625
4 Nov 20250.7178
24 Nov 20250.68259
1 Dec 20250.55491
4 Dec 20250.68259
27 Dec 20250.5856
28 Dec 20250.68259
1 Jan 20260.55491
4 Jan 20260.68259
18 Jan 20260.68702
23 Jan 20260.68259
1 Feb 20260.55491
4 Feb 20260.68259
1 Mar 20260.55491
4 Mar 20260.68259
31 May 20260.71517
6 Jun 20260.7201
10 Jun 20260.72405
11 Jun 20260.67721
15 Jun 20260.7907
23 Aug 20260.76952
30 Aug 20260.7907
5 Sep 20260.76952
6 Sep 20260.7907

57 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.7907Published2016-12-05Public PoC2017-10-11Index as of2026-09-06

The record had been public for 9 years, 9 months when this index was last written.

Published 2016-12-05 receipt · Public PoC 2017-10-11 receipt · Index as of 2026-09-06 derived

The pattern, elsewhere

This record is one instance of CWE-20, improper input validation. The index holds 13347 prior instances of this class, 73 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2022-47966matches 6 of 9KEV listed · 2023receipt
CVE-2022-29499matches 6 of 9KEV listed · 2022receipt
CVE-2021-21985 · VMware vCenter Server and VMware Cloud…matches 6 of 10KEV listed · 2021receipt
CVE-2021-44228 · Apache Log4j2matches 6 of 10KEV listed · 2021receipt
CVE-2018-19949 · QNAP Systems Inc. QTSmatches 6 of 10KEV listed · 2020receipt
CVE-2019-0604 · Microsoft SharePoint Servermatches 6 of 10KEV listed · 2019receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

13347 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

Siblings and hubs

Records related to this one

Its defect family

apache software foundation apache http server

Of the 3 records in this family that state one, this holds the lowest NVD CVSS score: 7.5.

Grouped by shared product and weakness, not by shared vulnerability. Each record's own state is on its own page.

Family membership: held values

This record is one of a group, and the group's page describes all of them. This page is kept and dated, and the defect family's own page is the one we offer for indexing: the whole group.

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What usually comes next

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