Evidence used
- CISA confirms exploitation in the wild.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.54% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-34926High confidence
Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
Trend Micro · Apex One
6.7MediumCVSS 3.1
Patch now
Patch availableCISA confirms exploitation in the wild and lists 2026-06-04 as the remediation due date.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Critical, raised 2 bands.upgradedsince 21 May 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Trend Micro Apex One and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
CISA confirms exploitation in the wild and lists 2026-06-04 as the remediation due date.
Patch available01
What, why and how
Trend Micro Apex One (on-premise) contains a directory traversal vulnerability that 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.
What
Trend Micro Apex One (on-premise) contains a directory traversal vulnerability that 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.
Why
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as .. that can resolve to a location that is outside of that directory.
How
An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Trend Micro Apex One (on-premise) contains a directory traversal vulnerability that 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.
Why
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as .. that can resolve to a location that is outside of that directory.
How
An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation Confirmed in the wild
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-05-21.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → Relative Path Traversal → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-23 ↗
CWE-23: Relative Path Traversal. The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as .. that can resolve to a location that is outside of that directory.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:LCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.ILowIntegrity impact: A successful attack can cause a limited loss.ALowAvailability impact: A successful attack can cause a limited loss.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Action
- Apply the fixed release for the affected product branch as recorded by JVN iPedia. Validate the exact product and build in the linked advisory before deployment.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 21 May 2026 · Last source change 22 May 2026, 12:47 UTC · CWE-23 · Relative Path Traversal
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-31284
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: removed remediation: jvndb.jvn.jp/JVNDB-2026-016802.html.security@trendmicro.com ↗
- Before
- remediation: jvndb.jvn.jp/JVNDB-2026-016802.html · vendor advisory: success.trendmicro.com/KA-0022974 · vendor advisory: success.trendmicro.com/KA-0023430
- After
- vendor advisory: success.trendmicro.com/KA-0022974 · vendor advisory: success.trendmicro.com/KA-0023430
- Affected versionsThe structured affected or fixed version information changed.CISA KEV ↗
- Before
- TrendAI Apex One: 2019 (14.0) < 14.0.0.17079; TrendAI Apex One as a Service: SaaS < 14.0.20731 · Fixed: [パッチを適用する] 開発者が提供する情報をもとにパッチを適用してください。 開発者は本脆弱性の対策として次のパッチをリリースしています。 TrendAI Apex One（オンプレミス版） サーバ：Service Pack 1 Critical Patch B18012 セキュリティエージェント：Agent Build 14.0.18012 Trend Micro Apex One as a Service サーバ：2026年4月のメンテナンスで修正済 セキュリティエージェント：Agent Build 14.0.20731 Trend Vision One Endpoint Security - Standard Endpoint Protection サーバ：2026年4月のメンテナンスで修正済 セキュリティエージェント：Agent Build 14.0.20731
- After
- TrendAI Apex One: 2019 (14.0) < 14.0.0.17079; TrendAI Apex One as a Service: SaaS < 14.0.20731 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Remediation statusRemediation status changed from Patch available to Awaiting fix.security@trendmicro.com ↗
- Before
- Patch available
- After
- Awaiting fix
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- 2019 (14.0) < 14.0.0.17079; SaaS < 14.0.20731 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- TrendAI Apex One: 2019 (14.0) < 14.0.0.17079; TrendAI Apex One as a Service: SaaS < 14.0.20731 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Affected versionsThe structured affected or fixed version information changed.JVN iPedia ↗
- Before
- TrendAI Apex One: 2019 (14.0) < 14.0.0.17079; TrendAI Apex One as a Service: SaaS < 14.0.20731 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- TrendAI Apex One: 2019 (14.0) < 14.0.0.17079; TrendAI Apex One as a Service: SaaS < 14.0.20731 · Fixed: [パッチを適用する] 開発者が提供する情報をもとにパッチを適用してください。 開発者は本脆弱性の対策として次のパッチをリリースしています。 TrendAI Apex One（オンプレミス版） サーバ：Service Pack 1 Critical Patch B18012 セキュリティエージェント：Agent Build 14.0.18012 Trend Micro Apex One as a Service サーバ：2026年4月のメンテナンスで修正済 セキュリティエージェント：Agent Build 14.0.20731 Trend Vision One Endpoint Security - Standard Endpoint Protection サーバ：2026年4月のメンテナンスで修正済 セキュリティエージェント：Agent Build 14.0.20731
- Remediation statusRemediation status changed from Awaiting fix to Patch available.JVN iPedia ↗
- Before
- Awaiting fix
- After
- Patch available
CVE published
Added to CISA KEV
Fixed release recorded from official guidance
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.