# CVE-2026-15911: Confluent Kafka Python Improper TLS Certificate Validation

> Remote attackers can intercept sensitive data via improper TLS validation in the HashiCorp Vault KMS integration of the Confluent Kafka Python client.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-r743-crv8-m3qr, openSUSE-SU-2026:12006-1

## What is CVE-2026-15911?

CVE-2026-15911 is a high-severity vulnerability in confluent-kafka, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Confluent Kafka Python client's HashiCorp Vault KMS integration could allow a remote attacker to obtain sensitive information due to improper TLS certificate validation.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-15911?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `python-confluent-kafka` | openSUSE:Tumbleweed | All versions | 2.15.1-1.1 |

## How do I fix CVE-2026-15911?

Apply the vendor's patch.

## Is CVE-2026-15911 being exploited?

There is no known exploitation of CVE-2026-15911 in the wild and no public exploit code.

Public exploit code:

- Disabled TLS Certificate Verification for HashiCorp Vault KMS in confluent-kafka (github_poc): https://github.com/rahulreddykarne/CVE-2026-15911-Confluent_Kafka

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15911 and fix it if it is affected.

What it is: CVE-2026-15911 is a high-severity vulnerability in confluent-kafka, published on 1 Oct 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-2026-15911 in the wild and no public exploit code.

Affected product: confluent-kafka. 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-2026-15911/ (Markdown: https://insights.sbomify.com/CVE-2026-15911/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15911
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15911
- OSV: https://osv.dev/vulnerability/CVE-2026-15911

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15911/
Summaries are generated and may contain mistakes; the official description above is the record.