vciy

CVE-2021-20453

INDEX BUILT · 2026-09-20

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IBM WebSphere Application Server 8.0, 8.5, and 9.0 is vulnerable to a XML External Entity Injection (XXE) attack when processing XML data

CVE-2021-204534 of 4 sources documented this
27

rank 27 = 1 + 21 + 0 + 5 + 0

rank@v1 · scheduled

Someone is already using it

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

EPSS 0.02563  ·  without this subject the record ranks 26

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 8.2, from NVD  ·  without this subject the record ranks 6

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 27

How much of the world it touches

NVD CPE configurations

3 products in the CPE ranges  ·  without this subject the record ranks 22

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 27

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$91,800over the next 30 days, if this record is yours
Movement-$351,000on 2022-04-01, the last material move, 4 years, 2 months before this reading
Basisassumeda published average, not your estate

$91,800 = $4.99M incident cost x 0.7179585840212677 exposure x 0.02563 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

0.02563EPSSNOT IN KEVas of 2026-09-20
Severity8.2 HIGHreceipt
Harmunauthenticated · networkreceipt
Exploitationnone in held sources
Defenseunaffected versions publishedreceipt
Movementscoring model changedreceipt
PLATEAU10Minimal movement since 2022-02-04, 1592 days at 0.03, as of 2026-06-15. arc-rules@v1

Foresight · where to check next

geoserverCVE-2019-13608SysAid On-PremNorth GridCVE-2019-967020453

This record is one instance of CWE-611, improper restriction of xml external entity reference. The index holds 1328 prior instances of this class, 8 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

Sources disagree here.

Scoring standard
IbmCVSS v3.0receipt
NVDCVSS v3.1receipt

Both shown, dated. We don't pick winners. disagreement-rules@v1

Running IBM WebSphere Application Server? Check your version

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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 confidentiality loss; partial availability lossreceipt
Scored fromCVSS v3.0 · the CNA's vectorreceipt
Weakness classCWE-611 Improper Restriction of XML External Entity Referencereceipt
Published consequencesCWE-611: Confidentiality: Read Application Data, Read Files or Directories; Integrity: Bypass Protection Mechanism; Availability: DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory)[email protected]

CISA KEV & Federal Remediation Deadline from the record and CISA

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

First unaffected version, by branchwebsphere application server 8.0.0.15; websphere application server 8.5.5.20; websphere application server 9.0.5.8receipt
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, the CNA8.2 HIGHreceipt
CVSS, NVD8.2 HIGHreceipt
Exploit probability0.02563 · top 16% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned byibmreceipt
Recorded changes17 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productIBM WebSphere Application Serverreceipt
Published rangesibm websphere application server >= 8.0.0.0 < 8.0.0.15; ibm websphere application server >= 8.5.0.0 < 8.5.5.20; ibm websphere application server >= 9.0.0.0 < 9.0.5.8receipt

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

IBM WebSphere Application Server 8.0, 8.5, and 9.0 is vulnerable to a XML External Entity Injection (XXE) attack when processing XML data. A remote attacker could exploit this vulnerability to expose sensitive information or consume memory resources. IBM X-Force ID: 196648. receipt

NVD's analysis a second authority

severity
8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
weakness
CWE-611
affected versions
ibm websphere application server >= 8.0.0.0 < 8.0.0.15; ibm websphere application server >= 8.5.0.0 < 8.5.5.20; ibm websphere application server >= 9.0.0.0 < 9.0.5.8

check it yourself ibm.com exchange.xforce.ibmcloud.com receipt

Dated events

2021-04-27EPSS moved 0.01 to 0.062022-01-06EPSS moved 0.06 to 0.232022-04-01EPSS moved 0.11 to 0.01

Movement the material steps

21 Apr 20210.00833
6 Jan 20220.22956 · crossed 0.10
4 Feb 20220.10855
1 Apr 20220.01055 · crossed 0.10
7 Mar 20230.00151 · scoring model v2023.03.01
17 Mar 20250.00433 · scoring model v2025.03.14
15 Jun 20260.02563 · scoring model v2026.06.15
Show all 17 observations
21 Apr 20210.00833
27 Apr 20210.06227
6 Jan 20220.22956
4 Feb 20220.10855
1 Apr 20220.01055
7 Mar 20230.00151
25 Nov 20230.00154
22 Apr 20240.00158
17 Dec 20240.00148
17 Mar 20250.00433
29 Mar 20250.00859
30 Mar 20250.00132
18 Nov 20250.00394
21 Nov 20250.00132
25 Nov 20250.00318
10 Dec 20250.00083
15 Jun 20260.02563

17 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 0.02563Published2021-04-20Index as of2026-06-15

The record had been public for 5 years, 1 month when this index was last written.

Published 2021-04-20 receipt · Index as of 2026-06-15 derived

The pattern, elsewhere

This record is one instance of CWE-611, improper restriction of xml external entity reference. The index holds 1328 prior instances of this class, 8 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2025-58360 · geoservermatches 8 of 9KEV listed · 2025receipt
CVE-2019-13608matches 7 of 8KEV listed · 2019receipt
CVE-2025-2775 · SysAid On-Premmatches 7 of 9KEV listed · 2025receipt
CVE-2025-2776 · SysAid On-Premmatches 7 of 9KEV listed · 2025receipt
CVE-2023-45727 · North Grid Corporation Proself…matches 7 of 9KEV listed · 2023receipt
CVE-2019-9670matches 6 of 8KEV 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

1328 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

ibm websphere application server

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

Family membership: held values

Nothing we hold separates this record from the others in its defect family. 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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