vciy

CVE-2023-45648

INDEX BUILT · 2026-09-20

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Apache Tomcat: Trailer header parsing too lenient

CVE-2023-456484 of 4 sources documented this
29

rank 29 = 1 + 13 + 7 + 8 + 0

rank@v1 · scheduled

Someone is already using it

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

EPSS 0.05848  ·  without this subject the record ranks 28

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 5.3, from NVD  ·  without this subject the record ranks 16

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

rose on 2026-02-18  ·  without this subject the record ranks 22

How much of the world it touches

NVD CPE configurations

9 products in the CPE ranges  ·  without this subject the record ranks 21

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 29

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$70,200over the next 30 days, if this record is yours
Movement+$538,000on 2026-02-18, the last material move, 3 months before this reading
Basisassumeda published average, not your estate

$70,200 = $4.99M incident cost x 0.24048551839932833 exposure x 0.05848 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

0.05848EPSSNOT IN KEVas of 2026-09-20
Severity5.3 MEDIUMreceipt
Harmunauthenticated · networkreceipt
Exploitationnone in held sources
Defensefix version namedreceipt
Movementthreshold crossedreceipt
RISING10Risen from 0.00045 to 0.05848 across 59 observations. arc-rules@v1

Foresight · where to check next

MicrosoftAdobe CommerceCVE-2022-47966CVE-2022-29499VMware vCenterApache Log4j245648

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 Tomcat? 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
ImpactPartial integrity lossreceipt
Scored fromCVSS v3.1 · NVD's vectorreceipt
Weakness classCWE-20 Improper Input Validationreceipt
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 in8.5.0receipt
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: Nothing observed in held sources.

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

Authority who says so

CVSS, NVD5.3 MEDIUMreceipt
Exploit probability0.05848 · top 7% of all CVEsreceipt
Blast breadth2 products across 2 vendorsderived
Assigned byapachereceipt
Recorded changes59 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productApache Software Foundation Apache Tomcatreceipt
Published rangesapache tomcat >= 8.5.0 < 8.5.94; apache tomcat >= 9.0.1 < 9.0.81; apache tomcat >= 10.1.1 < 10.1.14; apache tomcat 9.0.0receipt
Show all 9 published ranges
apache tomcat >= 8.5.0 < 8.5.94
apache tomcat >= 9.0.1 < 9.0.81
apache tomcat >= 10.1.1 < 10.1.14
apache tomcat 9.0.0
apache tomcat 10.1.0
apache tomcat 11.0.0
debian linux 10.0
debian linux 11.0
debian linux 12.0
Fixed in8.5.0receipt

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

Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M11, from 10.1.0-M1 through 10.1.13, from 9.0.0-M1 through 9.0.81 and from 8.5.0 through 8.5.93 did not correctly parse HTTP trailer headers. A specially crafted, invalid trailer header could cause Tomcat to treat a single request as multiple requests leading to the possibility of request smuggling when behind a reverse proxy. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M12 onwards, 10.1.14 onwards, 9.0.81 onwards or 8.5.94 onwards, which fix the issue. receipt

NVD's analysis a second authority

severity
5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
weakness
CWE-20
affected versions
apache tomcat >= 8.5.0 < 8.5.94; apache tomcat >= 9.0.1 < 9.0.81; apache tomcat >= 10.1.1 < 10.1.14; and 6 more, listed in full below
also scored by
5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

check it yourself lists.apache.org receipt

Dated events

2026-02-12EPSS moved 0.01 to 0.092026-06-15EPSS moved 0.62 to 0.06

Movement the material steps

11 Oct 20230.00045
17 Mar 20250.04605 · scoring model v2025.03.14
18 Feb 20260.53512 · crossed 0.10 and 0.50
4 Mar 20260.65268
15 Jun 20260.05848 · crossed 0.10 and 0.50 · scoring model v2026.06.15

This score more than doubled inside 72 hours. Both observations are in the full history below.

Show all 59 observations
11 Oct 20230.00045
17 Oct 20230.00157
4 Nov 20230.00222
16 Oct 20240.00269
11 Nov 20240.00382
17 Dec 20240.00447
17 Mar 20250.04605
19 Mar 20250.09311
20 Mar 20250.04605
27 Mar 20250.09311
28 Mar 20250.04605
29 Mar 20250.09311
30 Mar 20250.04605
15 Apr 20250.00732
1 May 20250.00694
4 May 20250.00732
1 Jun 20250.00694
4 Jun 20250.00732
18 Jun 20250.00753
1 Jul 20250.00713
2 Jul 20250.00694
4 Jul 20250.00732
23 Jul 20250.0054
1 Aug 20250.00511
4 Aug 20250.0054
16 Aug 20250.00555
28 Aug 20250.0054
1 Sep 20250.00511
4 Sep 20250.0054
1 Oct 20250.00694
4 Oct 20250.00732
27 Oct 20250.0054
28 Oct 20250.00732
1 Nov 20250.00694
4 Nov 20250.00732
18 Nov 20250.03959
21 Nov 20250.00732
1 Dec 20250.00694
4 Dec 20250.00732
27 Dec 20250.0054
28 Dec 20250.00732
1 Jan 20260.00694
4 Jan 20260.00732
1 Feb 20260.00694
4 Feb 20260.00732
12 Feb 20260.08662
18 Feb 20260.53512
19 Feb 20260.62958
1 Mar 20260.59349
4 Mar 20260.65268
5 Mar 20260.60431
9 Mar 20260.59736
21 Mar 20260.62371
28 Mar 20260.65906
7 Apr 20260.62371
8 Apr 20260.59475
22 May 20260.62748
2 Jun 20260.62079
15 Jun 20260.05848

59 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 0.05848Published2023-10-10Index as of2026-06-15

Exploit probability more than doubled between 2025-03-17 and 2025-03-19 (0.04605 → 0.09311) and the record had been public for 2 years, 8 months when this index was last written.

Published 2023-10-10 receipt · Index as of 2026-06-15 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-2026-32201 · Microsoft SharePoint Enterprise Server 2016matches 7 of 9KEV listed · 2026receipt
CVE-2025-54236 · Adobe Commercematches 6 of 9KEV listed · 2025receipt
CVE-2022-47966matches 5 of 8KEV listed · 2023receipt
CVE-2022-29499matches 5 of 8KEV listed · 2022receipt
CVE-2021-21985 · VMware vCenter Server and VMware Cloud…matches 5 of 9KEV listed · 2021receipt
CVE-2021-44228 · Apache Log4j2matches 5 of 9KEV listed · 2021receipt

"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 tomcat

Of the 9 records in this family, this is the only one whose title names trailer parsing too.

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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