CASCACascade Atlas

Evidence dossier

CVE-2026-34926

A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious…

Exploited in the wild (CISA KEV since May 21, 2026). trendmicro reports CVSS 3.1 6.7. EPSS estimates 12.7% exploit likelihood as of Aug 27, 2026.

63.9–70.0Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.

State
PUBLISHED
Published
May 21, 2026
Updated
May 22, 2026
Evidence coverage
85%

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
    trendmicro

    Record text: A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.

    Inspect raw assertion
    Field
    container
    Value
    A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.
    Original evidence ↗
  3. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 12.68% probability · 95.96th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.126820000000; percentile 0.959600000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date May 21, 2026 · first observed Jul 19, 2026

Exploit likelihood12.68%

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

SeverityCVSS 6.7

trendmicro · 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 ↗
trendmicroOriginal assertion
Record text

A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.

Inspect raw assertion
Field
container
Value
A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

12.68% probability · 95.96th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.126820000000; percentile 0.959600000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
2Underlying assertions
1Canonical products
2Target assertions
0Constraint assertions

Grouped from 1 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

3 scope groups

trendmicro · source assertedTrend Micro, Inc.TrendAI Apex OneDirect source scope
Affected: 2019 (14.0) to before 14.0.0.17079 (semver comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "2019 (14.0)", "lessThan": "14.0.0.17079", "versionType": "semver"}]
trendmicro · source assertedTrend Micro, Inc.TrendAI Apex One as a ServiceDirect source scope
Affected: SaaS to before 14.0.20731 (semver comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "SaaS", "lessThan": "14.0.20731", "versionType": "semver"}]
NVD CPE · APPLICATIONtrendmicroapex_oneVulnerable target · 2 assertions
Any version (unconstrained) (< 14.0.0.17079); Any version (unconstrained) (< 14.0.20731)Canonical identity product-c36b03ede89735893cf5eb7227d4471fd5a59b5023d788d61a15bc2c37404e58Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:trendmicro:apex_one:*:*:*:*:saas:windows:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    through excluding 14.0.20731
    Match ID
    322053cc-d396-412e-9f81-7640fe9db7bd
  2. cpe:2.3:a:trendmicro:apex_one:*:*:*:*:on-premises:windows:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 14.0.0.17079
    Match ID
    6f20657b-98a4-46be-8481-12060262c850

Affected-product evidence

Accepted scope and product mapping

0 canonical links · 2 source-reported links

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
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
0beccc3c-93c1-4b75-84b2-d805975bce821b9f7715-db10-44ff-bbb8-de8a9f77a87c
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
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
4e089af2-6b7f-4c39-84d9-77b57c04290a7a4c56b6-4536-4de4-9b8f-f8b6cd4dc433

Assessments

CVSS by origin

6.7
security@trendmicro.comCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
6.7
trendmicroCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L

Direct CVE/CNA normalized decisions

6.7Priority eligible

trendmicro

CVSS 3.1 · Primary · Original assertion · rank 1

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Validation
Valid match
Recomputed
6.7
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.