# CVE-2026-97840: DNS Server out-of-bounds read information disclosure

Source: https://junglewise.ai/threats/cve-2026-97840-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-97840 · Severity: medium · CVSS 6.5 · Published 2026-10-13

A DNS server component contains an out-of-bounds read vulnerability that allows an authenticated attacker to read sensitive information from server memory over the network. An attacker with valid credentials could exploit this to access data that should not be accessible, potentially exposing configuration details, encryption keys, or other confidential information.

Technologies: [Microsoft DNS Server](https://junglewise.ai/threats/technologies/microsoft-dns-server), [Microsoft Windows 10 1607](https://junglewise.ai/threats/technologies/windows-10-1607), [Microsoft Windows 10 1809](https://junglewise.ai/threats/technologies/windows-10-1809), [Microsoft Windows 10 21h2](https://junglewise.ai/threats/technologies/windows-10-21h2), [Microsoft Windows 10 22h2](https://junglewise.ai/threats/technologies/windows-10-22h2), [Microsoft Windows 11 23h2](https://junglewise.ai/threats/technologies/windows-11-23h2), [Microsoft Windows 11 24h2](https://junglewise.ai/threats/technologies/windows-11-24h2), [Microsoft Windows 11 25h2](https://junglewise.ai/threats/technologies/windows-11-25h2), [Microsoft Windows 11 26h1](https://junglewise.ai/threats/technologies/windows-11-26h1), [Microsoft Windows 11 26h2](https://junglewise.ai/threats/technologies/windows-11-26h2), [Microsoft Windows Server 2012](https://junglewise.ai/threats/technologies/windows-server-2012), [Microsoft Windows Server 2016](https://junglewise.ai/threats/technologies/windows-server-2016), [Microsoft Windows Server 2019](https://junglewise.ai/threats/technologies/windows-server-2019), [Microsoft Windows Server 2022](https://junglewise.ai/threats/technologies/windows-server-2022), [Microsoft Windows Server 2025](https://junglewise.ai/threats/technologies/windows-server-2025). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-97840 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-97840 being exploited in the wild.

**How severe is CVE-2026-97840?** Medium severity, with a CVSS score of 6.5, published 13 October 2026.

**Which products and versions are affected?** Microsoft DNS Server.

**Is there a fix for CVE-2026-97840?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-97840 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-97840?** Check whether you run Microsoft DNS Server, Microsoft Windows 10 1607, Microsoft Windows 10 1809 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read vulnerability in DNS Server allows an authenticated attacker to read beyond allocated memory boundaries. The vulnerability requires prior authentication and network access to the DNS service. Successful exploitation results in disclosure of sensitive information from the server's memory.

## Affected products

- Microsoft DNS Server

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97840](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97840)

## Related threats

- [Windows DNS Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-97844-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-97843-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-97842-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-97841-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Microsoft DNS Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-97839-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)