CASCACascade Atlas

Evidence dossier

CVE-2020-11899

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

Exploited in the wild (CISA KEV since Mar 3, 2022). NVD reports CVSS 3.1 5.4. EPSS estimates 18.6% exploit likelihood as of Aug 27, 2026.

67.4–68.3Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

State
PUBLISHED
Published
Jun 17, 2020
Updated
Oct 21, 2025
Evidence coverage
97%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    mitre

    Record text: The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

    Inspect raw assertion
    Field
    container
    Value
    The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Treck TCP/IP stack Out-of-Bounds Read Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Treck TCP/IP stack Out-of-Bounds Read Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 18.56% probability · 97.04th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.185640000000; percentile 0.970380000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 3, 2022 · first observed Jul 19, 2026

Exploit likelihood18.56%

FIRST EPSS · score date Aug 27, 2026 · 97th percentile · first observed Aug 27, 2026

SeverityCVSS 5.4

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
mitreOriginal assertion
Record text

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

Inspect raw assertion
Field
container
Value
The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Treck TCP/IP stack Out-of-Bounds Read Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Treck TCP/IP stack Out-of-Bounds Read Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

18.56% probability · 97.04th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.185640000000; percentile 0.970380000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
7Underlying assertions
7Canonical products
4Target assertions
3Constraint assertions

Grouped from 7 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

8 scope groups

mitre · source assertedn/an/aDirect source scope
Affected: n/a
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "n/a"}]
NVD CPE · HARDWAREdellwyse_5030Environmental constraint · 1 assertions
Version not applicableCanonical identity product-739a5da5a75f6f9c983b33191fce3eadd99a40fbd74f81579a4be65d9d393674Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:dell:wyse_5030:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    3 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    6733903c-b9d3-4476-ae6c-b224ae5bf01b
NVD CPE · OPERATING SYSTEMdellwyse_5030_firmwareVulnerable target · 1 assertions
Version not applicableCanonical identity product-ddf5d3ffbc6151d64d6389594beb31c1b17a6a8d264aa314cf5d694cff6fab14Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:dell:wyse_5030_firmware:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    db1c2400-6395-4495-ae4e-2cfc87ee98f1
NVD CPE · HARDWAREdellwyse_5050_all-in-oneEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-a3be7e2f50c8c258dfcd15729507588189c2e052710b61bf0b78c2a70ffd7466Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:dell:wyse_5050_all-in-one:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    6966c461-daff-4f71-a209-44fa1bdd6af9
NVD CPE · OPERATING SYSTEMdellwyse_5050_all-in-one_firmwareVulnerable target · 1 assertions
Version not applicableCanonical identity product-488bd0d2c01146bfb229be3eb803f8f6e73c78ba505dde681647f78adf42cfbbLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:dell:wyse_5050_all-in-one_firmware:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    fb990439-8d74-4993-ad30-c7a365c96941
NVD CPE · HARDWAREdellwyse_7030Environmental constraint · 1 assertions
Version not applicableCanonical identity product-bcf003d28d9ef284f9e3dc06b36e450ede688758cd0cbd7c47118a9d566c9087Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:dell:wyse_7030:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    2 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    abafd47a-32ba-4c10-9bc3-d11a4fa57dbb
NVD CPE · OPERATING SYSTEMdellwyse_7030_firmwareVulnerable target · 1 assertions
Version not applicableCanonical identity product-49c8ba3975574b50f1aee6b53ab1c6c3e77ba186a4a87b162b299ce56c58fd9eLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:dell:wyse_7030_firmware:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b12d74a6-d734-41d6-a998-1af09360bc7b
NVD CPE · APPLICATIONtrecktcp/ipVulnerable target · 1 assertions
Any version (unconstrained) (< 6.0.1.66)Canonical identity product-fd2492cf554ccf6d89c0e7353f221385368d1f3168d406ccb37b3da7cc06e636Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:treck:tcp\/ip:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 6.0.1.66
    Match ID
    51f9d0df-d9f0-4183-ac07-c799effe36c8

Affected-product evidence

Accepted scope and product mapping

4 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-672f7be6cef424a0fe9d0805383bdc16e8f97d7201e4086c9232a0a4cd55bd8d · product-488bd0d2c01146bfb229be3eb803f8f6e73c78ba505dde681647f78adf42cfbb

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
4c191c98-046a-475b-95d0-5da62fb9ee20
Mapping establishedEvidence supported

vendor-672f7be6cef424a0fe9d0805383bdc16e8f97d7201e4086c9232a0a4cd55bd8d · product-49c8ba3975574b50f1aee6b53ab1c6c3e77ba186a4a87b162b299ce56c58fd9e

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
f7c88a05-0cfa-4893-a6ff-539b3f8a4a90
Mapping establishedEvidence supported

vendor-672f7be6cef424a0fe9d0805383bdc16e8f97d7201e4086c9232a0a4cd55bd8d · product-ddf5d3ffbc6151d64d6389594beb31c1b17a6a8d264aa314cf5d694cff6fab14

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
b1e57f6e-ec38-435d-9394-dc9ef9ff8bd3
Mapping establishedEvidence supported

vendor-a67c62aa351454abfe002a5e56f9d83b709a41c97333980e6636ddb50a7317df · product-fd2492cf554ccf6d89c0e7353f221385368d1f3168d406ccb37b3da7cc06e636

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
9e1b039c-aa5b-428e-bd5a-996d990d3d53
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
b7de98dd-6015-4247-bcef-30112e956b56

Assessments

CVSS by origin

5.4
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
4.8
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:A/AC:L/Au:N/C:N/I:P/A:P
5.4
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
5.4
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Direct CVE/CNA normalized decisions

5.4Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Validation
Valid match
Recomputed
5.4
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.