# CVE-2026-47840: LDAP StartTLS unconditionally disables hostname verification

> A network attacker can bypass TLS hostname verification in LDAP StartTLS to steal credentials and forge admin group memberships in CloudFoundry UAA deployments.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jul 2026
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-rh75-5vxf-83m5

## What is CVE-2026-47840?

CVE-2026-47840 is a high-severity vulnerability in CloudFoundry Foundation Cf-deployment, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A network attacker positioned between UAA and its LDAP directory can impersonate the directory using any certificate from any trusted CA, then harvest the LDAP bind password and every end-user password sent during simple-bind authentication, and return forged group memberships that grant themselves admin scopes. This affects every deployment that authenticates users against LDAP over StartTLS.
Affected versions: UAA versions prior to v78.13.0; Cf-deployment versions prior to v56.2.0.

## Which versions are affected by CVE-2026-47840?


## How do I fix CVE-2026-47840?

No fix has been published for CVE-2026-47840 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47840 being exploited?

There is no known exploitation of CVE-2026-47840 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47840 and fix it if it is affected.

What it is: CVE-2026-47840 is a high-severity vulnerability in CloudFoundry Foundation Cf-deployment, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-47840 in the wild and no public exploit code.

Affected product: CloudFoundry Foundation Cf-deployment. 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-2026-47840/ (Markdown: https://insights.sbomify.com/CVE-2026-47840/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47840
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47840
- OSV: https://osv.dev/vulnerability/CVE-2026-47840

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47840/
Summaries are generated and may contain mistakes; the official description above is the record.