# CVE-2026-3039: BIND 9 server memory exhaustion during GSS-API TKEY negotiation

> Attackers can cause memory exhaustion and denial of service in BIND servers configured for GSS-API TKEY authentication by sending malicious packets.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 May 2026
- **Updated:** 17 Sep 2026
- **Also known as:** ALPINE-CVE-2026-3039, AZL-87087, BELL-CVE-2026-3039, CLSA-2026-1780054328, CLSA-2026-1780054583, CLSA-2026-1780407449, CLSA-2026-1781168947, DEBIAN-CVE-2026-3039, ECHO-ea81-22aa-6506, GHSA-p65f-mhrm-vhrc, MINI-565j-w7pf-7qv4, UBUNTU-CVE-2026-3039

## What is CVE-2026-3039?

CVE-2026-3039 is a high-severity denial of service vulnerability in Isc Bind, published on 20 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets.  Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments.
This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-771 (Missing Reference to Active Allocated Resource)

## Which versions are affected by CVE-2026-3039?

It affects 1 product.


Products: Isc Bind.

## How do I fix CVE-2026-3039?

Apply the vendor's patch.

## Is CVE-2026-3039 being exploited?

There is no known exploitation of CVE-2026-3039 in the wild and no public exploit code.

## Other vulnerabilities in Isc Bind

- [CVE-2008-0122](https://insights.sbomify.com/CVE-2008-0122/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0010](https://insights.sbomify.com/CVE-2001-0010/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0011](https://insights.sbomify.com/CVE-2001-0011/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0013](https://insights.sbomify.com/CVE-2001-0013/): Memory corruption in n/a (critical 10.0)
- [CVE-2000-1029](https://insights.sbomify.com/CVE-2000-1029/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3039 and fix it if it is affected.

What it is: CVE-2026-3039 is a high-severity denial of service vulnerability in Isc Bind, published on 20 May 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-2026-3039 in the wild and no public exploit code.

Affected product: Isc Bind. 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-2026-3039/ (Markdown: https://insights.sbomify.com/CVE-2026-3039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3039
- OSV: https://osv.dev/vulnerability/CVE-2026-3039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3039/
Summaries are generated and may contain mistakes; the official description above is the record.