# CVE-2026-0397: Information disclosure via CORS misconfiguration

> An attacker can extract configuration data from the PowerDNS DNSdist dashboard via CORS misconfiguration if the internal webserver is enabled.

- **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 31 Mar 2026
- **Updated:** 31 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-0397, GHSA-gjv7-4r9p-7hmx, UBUNTU-CVE-2026-0397

## What is CVE-2026-0397?

CVE-2026-0397 is a low-severity vulnerability in PowerDNS DNSdist, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

When the internal webserver is enabled (default is disabled), an attacker might be able to trick an administrator logged to the dashboard into visiting a malicious website and extract information about the running configuration from the dashboard. The root cause of the issue is a misconfiguration of the Cross-Origin Resource Sharing (CORS) policy.

Weakness: CWE-942 (Permissive Cross-domain Security Policy with Untrusted Domains)

## Which versions are affected by CVE-2026-0397?

It affects 1 product.


Products: Powerdns Dnsdist.

## How do I fix CVE-2026-0397?

Change a configuration setting.

## Is CVE-2026-0397 being exploited?

There is no known exploitation of CVE-2026-0397 in the wild and no public exploit code.

## Other vulnerabilities in PowerDNS DNSdist

- [CVE-2017-7557](https://insights.sbomify.com/CVE-2017-7557/): Cross-site request forgery in dnsdist (high 8.8)
- [CVE-2026-33593](https://insights.sbomify.com/CVE-2026-33593/): Denial of service via crafted DNSCrypt query (high 7.5)
- [CVE-2026-33602](https://insights.sbomify.com/CVE-2026-33602/): Off-by-one access when processing crafted UDP responses (medium 6.5)
- [CVE-2026-24029](https://insights.sbomify.com/CVE-2026-24029/): DNS over HTTPS ACL bypass (medium 6.5)
- [CVE-2026-27853](https://insights.sbomify.com/CVE-2026-27853/): Out-of-bounds write when rewriting large DNS packets (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0397 and fix it if it is affected.

What it is: CVE-2026-0397 is a low-severity vulnerability in PowerDNS DNSdist, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-0397 in the wild and no public exploit code.

Affected product: PowerDNS DNSdist. 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-2026-0397/ (Markdown: https://insights.sbomify.com/CVE-2026-0397/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0397
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0397
- OSV: https://osv.dev/vulnerability/CVE-2026-0397

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0397/
Summaries are generated and may contain mistakes; the official description above is the record.