CASCACascade Atlas

Evidence dossier

CVE-2025-6554

Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page.

Exploited in the wild (CISA KEV since Jul 2, 2025). CISA-ADP reports CVSS 3.1 8.1. EPSS estimates 12.7% exploit likelihood as of Aug 27, 2026.

70.0–71.6Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)

State
PUBLISHED
Published
Jun 30, 2025
Updated
Oct 21, 2025
Evidence coverage
95%

Evidence chronology

What was known when

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

    Record text: Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)

    Inspect raw assertion
    Field
    container
    Value
    Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)
    Original evidence ↗
  2. 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 ↗
  3. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Google Chromium V8 Type Confusion Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Google Chromium V8 Type Confusion Vulnerability
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 12.72% probability · 95.97th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.127230000000; percentile 0.959690000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Jul 2, 2025 · first observed Jul 19, 2026

Exploit likelihood12.72%

FIRST EPSS · score date Aug 27, 2026 · 96th percentile · first observed Aug 27, 2026

SeverityCVSS 8.1

CISA-ADP · 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

ChromeOriginal assertion
Record text

Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)

Inspect raw assertion
Field
container
Value
Type confusion in V8 in Google Chrome prior to 138.0.7204.96 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page. (Chromium security severity: High)
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
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 ↗
CISA KEVOriginal assertion
Exploitation cataloged

Google Chromium V8 Type Confusion Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Google Chromium V8 Type Confusion Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

12.72% probability · 95.97th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.127230000000; percentile 0.959690000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
5Underlying assertions
4Canonical products
2Target assertions
3Constraint assertions

Grouped from 4 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

5 scope groups

Chrome · source assertedGoogleChromeDirect source scope
Affected: 138.0.7204.96 to before 138.0.7204.96 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "138.0.7204.96", "lessThan": "138.0.7204.96", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMapplemacosEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-d6f53ba981bb58ea2b0d24855b8ff4a18555e3a17a9dce0d38460a69537bbc63Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    387021a0-af36-463c-a605-32ea7dac172e
NVD CPE · APPLICATIONgooglechromeVulnerable target · 2 assertions
Any version (unconstrained) (< 138.0.7204.92); Any version (unconstrained) (< 138.0.7204.96)Canonical identity product-6239ec405e2e1cdd75fd8ed01bb6845a448ecca3c3edcc8b0c5ccc2adb8b6bcdLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 138.0.7204.92
    Match ID
    a4d914da-1710-47f0-be81-741837318791
  2. cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 138.0.7204.96
    Match ID
    5a92f452-e80d-4c80-be35-7cec05dc959a
NVD CPE · OPERATING SYSTEMlinuxlinux_kernelEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-0eda7a801761be4590f267cf319481c8c0aaa30546d99cc064edf77989ce05c9Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    703af700-7a70-47e2-bc3a-7fd03b3ca9c1
NVD CPE · OPERATING SYSTEMmicrosoftwindowsEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-6a798dc931affc038ba266631a506d54b455ffebd96b4fae68f77b6bd7aef178Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    0 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a2572d17-1de6-457b-99cc-64afd54487ea

Affected-product evidence

Accepted scope and product mapping

1 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-88869ec57256fdf5d0b9ffd6f3d141ad371acdd6f81405ddb6c5e9e45b10869c · product-6239ec405e2e1cdd75fd8ed01bb6845a448ecca3c3edcc8b0c5ccc2adb8b6bcd

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
647e280d-0784-494d-bd3b-d48607719f25f325731a-5a89-46a9-8d86-dc9a771913bd
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
0122faf9-d547-4cea-87a9-9eccb5707c28

Assessments

CVSS by origin

8.1
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
8.1
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Direct CVE/CNA normalized decisions

8.1Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Validation
Valid match
Recomputed
8.1
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.