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

> Attackers can deny access to static files in Eclipse Vert.x Web by crafting specific URIs that exploit improper URI normalization in the static handler cache.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jan 2026
- **Updated:** 15 Jan 2026
- **Also known as:** CLEANSTART-2026-EK29154, CLEANSTART-2026-HZ12823, CLEANSTART-2026-ZX15129, ECHO-381d-f8c0-9386, GHSA-cphf-4846-3xx9, MINI-2738-6745-57jq, MINI-2w92-m7jh-998c, MINI-4gjv-q2rr-7w95, MINI-5c9v-2m9c-4hc8, MINI-5gj7-v6jr-mq53, MINI-7rh4-pcv8-8vph, MINI-9ch8-wr77-gc36, MINI-c27r-hqwm-qcp3, MINI-fq9v-7fpf-cwc7, MINI-fwp4-6ph3-w3qq, MINI-j9q3-98q6-r6pv, MINI-jpqr-mxfw-pmww, MINI-p483-68p4-7ccv, MINI-prj6-q539-rcp8, MINI-q4hf-hwpr-6ph7, MINI-r3p4-6j3q-65jq, MINI-w4fx-88x7-m9vq, MINI-wx3v-h66x-cjgh, MINI-xhr7-m4vg-3c4h

## What is CVE-2026-1002?

CVE-2026-1002 is a medium-severity denial of service vulnerability in Eclipse Vert.x, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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);

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2026-1002?

4 open source packages ship an affected version, including io.vertx:vertx-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.vertx:vertx-core` | Maven | All versions | 4.5.24 |
| `io.vertx:vertx-core` | Maven | All versions | 4.5.24 |
| `io.vertx:vertx-core` | Maven | From 5.0.0.CR1 | 5.0.7 |
| `io.vertx:vertx-core` | Maven | From 5.0.0.CR1 | 5.0.7 |

Products: Eclipse Vert.x-Web.

## How do I fix CVE-2026-1002?

Upgrade io.vertx:vertx-core to a fixed version for your release line: 4.5.24 or 5.0.7.

## Is CVE-2026-1002 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1002 exists.

## Other vulnerabilities in Eclipse Vert.x

- [CVE-2020-35217](https://insights.sbomify.com/CVE-2020-35217/): Cross-Site Request Forgery in Vert.x-Web framework (high 8.8)
- [CVE-2023-24815](https://insights.sbomify.com/CVE-2023-24815/): Disclosure of classpath resources on Windows when mounted on a wildcard route in vertx-web (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1002 and fix it if it is affected.

What it is: CVE-2026-1002 is a medium-severity denial of service vulnerability in Eclipse Vert.x, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1002 exists.

Affected packages and fixed versions:
- io.vertx:vertx-core (Maven): affected all versions; fixed in 4.5.24
- io.vertx:vertx-core (Maven): affected all versions; fixed in 4.5.24
- io.vertx:vertx-core (Maven): affected from 5.0.0.CR1; fixed in 5.0.7
- io.vertx:vertx-core (Maven): affected from 5.0.0.CR1; fixed in 5.0.7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-1002/ (Markdown: https://insights.sbomify.com/CVE-2026-1002/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1002
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1002
- OSV: https://osv.dev/vulnerability/CVE-2026-1002

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1002/
Summaries are generated and may contain mistakes; the official description above is the record.