# CVE-2026-52833: Nuclio code injection in Java runtime build.gradle

Source: https://junglewise.ai/threats/cve-2026-52833-nuclio-code-injection-in-java-runtime-build-gradle  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-02. Updated: 2026-07-16  
License: CC BY 4.0 with a link back

CVE-2026-52833 · Severity: high · CVSS 8 · Published 2026-09-02

Nuclio, an open-source serverless platform, contains a vulnerability in its Java function builder. An unauthenticated attacker can send a specially crafted request to the Dashboard API that injects malicious code into the build process. This allows the attacker to execute arbitrary commands as a root user within the build environment, potentially leading to the theft of cloud credentials, tampering with software artifacts, or further access into the internal network.

Technologies: [github.com/nuclio/nuclio (Go)](https://junglewise.ai/threats/technologies/github-com-nuclio-nuclio), [Nuclio](https://junglewise.ai/threats/technologies/nuclio). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Nuclio](https://junglewise.ai/threats/vendors/nuclio).

## Quick answers

**Is CVE-2026-52833 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-52833 being exploited in the wild.

**How severe is CVE-2026-52833?** High severity, with a CVSS score of 8, published 2 September 2026.

**Which products and versions are affected?** github.com/nuclio/nuclio (Go) < 1.16.5, SEMVER:introduced=0, SEMVER:introduced=0,fixed=1.16.5; Nuclio <= 1.15.27.

**Is there a fix for CVE-2026-52833?** Yes. github.com/nuclio/nuclio (Go): upgrade to 1.16.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-52833 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-52833?** Check whether you run github.com/nuclio/nuclio (Go) or Nuclio at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/nuclio/nuclio (Go): upgrade to 1.16.5 or later

  ```sh
  go get github.com/nuclio/nuclio@v1.16.5
  ```


## Technical details

The vulnerability exists in 'pkg/processor/build/runtime/java/runtime.go' where the 'createGradleBuildScript' function uses Go's 'text/template' package to generate a 'build.gradle' file. The 'runtimeAttributes.repositories' field is rendered using the '{{ . }}' action without any escaping or validation. An attacker can provide a string containing a closing brace '}' to break out of the 'repositories' block and inject arbitrary Groovy statements. These statements are executed unconditionally by Gradle during the configuration phase. Since the Dashboard API often runs with NOP authentication by default, this can be exploited without credentials. The build container typically runs as root, and depending on the environment, may have access to Kubernetes ServiceAccount tokens or cloud instance metadata (IMDS).

## Affected products

- Nuclio Nuclio <= 1.15.27

## Identifiers

- CVE-2026-52833
- GHSA-3v79-m2cg-89ww
- GO-2026-6004

## Timeline

- 2026-05-17: other: Vulnerability dynamically verified on version 1.15.27
- 2026-06-05: advisory: GitHub Advisory published
- 2026-07-16: disclosed: CVE-2026-52833 assigned
- 1.16.5: patched: Fixed in version 1.16.5

## References

- [https://api.github.com/users/j311yl0v3u](https://api.github.com/users/j311yl0v3u)
- [https://github.com/j311yl0v3u](https://github.com/j311yl0v3u)
- [https://api.github.com/users/j311yl0v3u/gists%7B/gist_id%7D](https://api.github.com/users/j311yl0v3u/gists%7B/gist_id%7D)
- [https://api.github.com/users/j311yl0v3u/repos](https://api.github.com/users/j311yl0v3u/repos)
- [https://avatars.githubusercontent.com/u/102125416?v=4](https://avatars.githubusercontent.com/u/102125416?v=4)
- [https://api.github.com/users/j311yl0v3u/events%7B/privacy%7D](https://api.github.com/users/j311yl0v3u/events%7B/privacy%7D)

## Related threats

- [Nuclio OS command injection in dashboard namespace validation](https://junglewise.ai/threats/cve-2026-79756-nuclio-os-command-injection-in-dashboard-namespace-validation)
- [Nuclio command injection in Docker platform via namespace filter](https://junglewise.ai/threats/cve-2026-79755-nuclio-command-injection-in-docker-platform-via-namespace-filter)
- [Nuclio Dashboard command injection in Kaniko builder](https://junglewise.ai/threats/cve-2026-79754-nuclio-dashboard-command-injection-in-kaniko-builder)
- [Nuclio Dashboard path traversal in spec.handler allows arbitrary file write](https://junglewise.ai/threats/cve-2026-52832-nuclio-dashboard-path-traversal-in-spec-handler-allows-arbitrary)
- [Nuclio command injection in cron trigger event headers and body](https://junglewise.ai/threats/cve-2026-52831-nuclio-command-injection-in-cron-trigger-event-headers-and-body)