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CVE Record

CVE-2026-1002: Eclipse Vert.x Web static handler file access denial

The Vert.x Web static handler component cache can be manipulated to deny the access to static files served by the handler using specifically crafted request URI. The issue comes from an improper implementation of the C. rule of section 5.2.4 of RFC3986 and is fixed in Vert.x Core component (used by Vert.x Web): https://github.com/eclipse-vertx/vert.x/pull/5895 Steps to reproduce Given a file served by the static handler, craft an URI that introduces a string like bar%2F..%2F after the last / char to deny the access to the URI with an HTTP 404 response. For example https://example.com/foo/index.html can be denied with https://example.com/foo/bar%2F..%2Findex.html Mitgation Disabling Static Handler cache fixes the issue. StaticHandler staticHandler = StaticHandler.create().setCachingEnabled(false);

MediumCVSS 6.9Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2026-1002 lets an unauthenticated remote user make specific static files served by Eclipse Vert.x Web return 404 errors. This is a targeted availability issue, not evidence of data theft or code execution. Business impact depends on whether critical web assets are served through the affected static handler cache.

Executive priority

Treat as a moderate availability risk. Prioritize systems where blocked static files could disrupt customer access, login flows, documentation, or application front ends. This does not currently indicate ransomware-style urgency, data exposure, or remote code execution based on provided sources.

Technical view

The Vert.x Web static handler cache can be manipulated using crafted request URIs because of improper RFC3986 path processing in Vert.x Core. Affected evidence lists Eclipse Vert.x versions 4.0.0 and 5.0.0. The result is denial of access to static files served by the handler. CVSS v4.0 score is 6.9, medium.

Likely exposure

Applications using Eclipse Vert.x Web StaticHandler with caching enabled are the likely exposure point. Internet-facing services serving important static content through this component have higher operational risk. The source bundle does not identify affected downstream products or a fixed release version.

Exploitation context

The CVE describes network, unauthenticated, low-complexity exploitation causing HTTP 404 denial for targeted static files. The GitHub issue includes reproduction details, but CISA KEV is false in the provided data. There is no supplied evidence of broad active exploitation.

Researcher notes

Root cause is described as improper implementation of RFC3986 section 5.2.4 rule C, mapped to CWE-444. The fix is in Vert.x Core PR 5895. Evidence supports cache-based denial of static file access only; do not assume file disclosure, privilege escalation, or RCE.

Mitigation direction

  • Disable StaticHandler caching where operationally acceptable.
  • Track Eclipse Vert.x guidance and apply the Vert.x Core fix when available.
  • Prioritize internet-facing apps serving critical static assets.
  • Review dependency manifests for io.vertx and affected Vert.x versions.

Validation and detection

  • Inventory services using Eclipse Vert.x Web StaticHandler.
  • Confirm whether StaticHandler caching is enabled.
  • Check deployed Vert.x versions against vendor advisories.
  • In staging, verify static files remain accessible after malformed encoded-path requests.
  • Monitor logs for unusual 404 spikes on static assets.
Prepared
Confidence
medium
Sources
4

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-444: Exact CWE lookup

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Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-1002 mapping review

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Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.9 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.9CVSS 4.0MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L——Primary CVE score

Vulnerability scoring details

Base CVSS 4.0 score

6.9Medium
CVSS 4.0 vector shape for CVE-2026-1002Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Eclipse Vert.xEclipse Vert.xio.vertx, 4.0.0, 5.0.0unaffected
Weakness

CWE details

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-444 · source CWE mapping

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.