# CVE-2026-59299: Composition lookup can potentially poison base function in Spring Cloud Function

> Attackers can poison base functions via composition lookup in Spring Cloud Function, potentially leading to arbitrary code execution.

- **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** GHSA-r954-5cwm-rfh6

## What is CVE-2026-59299?

CVE-2026-59299 is a low-severity code injection vulnerability in Spring Cloud Function, published on 27 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Composition lookup can potentially poison base function in Spring Cloud Function.
Spring Cloud Function 5.0.0 - 5.0.3
Spring Cloud Function 4.3.0 - 4.3.4
Spring Cloud Function 4.2.0 - 4.2.7
Spring Cloud Function 3.2.16 and earlier

Weakness: CWE-471 (Modification of Assumed-Immutable Data (MAID))

## Which versions are affected by CVE-2026-59299?

It affects 1 product.


Products: Vmware Spring Cloud Function.

## How do I fix CVE-2026-59299?

Upgrade to a fixed version.

## Is CVE-2026-59299 being exploited?

There is no known exploitation of CVE-2026-59299 in the wild and no public exploit code.

## Other vulnerabilities in Spring Cloud Function

- [CVE-2022-22979](https://insights.sbomify.com/CVE-2022-22979/): Denial of Service in Spring Cloud Function (high 7.5)
- [CVE-2026-40989](https://insights.sbomify.com/CVE-2026-40989/): Self Routing guard bypassed via function composition (medium 5.7)
- [CVE-2026-40990](https://insights.sbomify.com/CVE-2026-40990/): Unbounded cache for function definitions (medium 5.7)
- [CVE-2026-59297](https://insights.sbomify.com/CVE-2026-59297/): Spring Cloud Function can incorrectly determine if URI is secure (low 3.1)
- [CVE-2026-59298](https://insights.sbomify.com/CVE-2026-59298/): Potential for improper filtering of HTTP headers in Spring Cloud Function (low 3.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59299 and fix it if it is affected.

What it is: CVE-2026-59299 is a low-severity code injection vulnerability in Spring Cloud Function, published on 27 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-59299 in the wild and no public exploit code.

Affected product: Spring Cloud Function. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-59299/ (Markdown: https://insights.sbomify.com/CVE-2026-59299/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59299
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59299
- OSV: https://osv.dev/vulnerability/CVE-2026-59299

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59299/
Summaries are generated and may contain mistakes; the official description above is the record.