# CVE-2026-69598: Microsoft Windows iSCSI buffer overflow

Source: https://junglewise.ai/threats/cve-2026-69598-microsoft-windows-iscsi-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-69598 · Severity: high · CVSS 8.8 · Published 2026-09-08

Windows iSCSI is a storage networking protocol used to connect servers to disk storage over IP networks. An attacker can exploit an incorrect buffer size calculation to execute arbitrary code remotely without authentication, potentially gaining full control of affected systems and compromising sensitive data or disrupting operations.

Technologies: [Microsoft Windows iSCSI](https://junglewise.ai/threats/technologies/windows-iscsi). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-69598 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-69598 being exploited in the wild.

**How severe is CVE-2026-69598?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows iSCSI.

**Is there a fix for CVE-2026-69598?** 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-2026-69598 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-69598?** Check whether you run Microsoft Windows iSCSI. 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

A buffer overflow vulnerability exists in Windows iSCSI due to incorrect calculation of buffer size, allowing remote code execution. The vulnerability is reachable over the network without requiring authentication. An attacker can send a specially crafted iSCSI packet to trigger the buffer overflow and execute arbitrary code with the privileges of the iSCSI service. The attack vector is network-based, and no user interaction is required to exploit the flaw.

## Affected products

- Microsoft Windows iSCSI

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69598](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69598)

## Related threats

- [Microsoft Windows iSCSI use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-105518-use-after-free-in-windows-iscsi-allows-an-unauthorized-attacker)
- [Microsoft Windows iSCSI heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-70095-heap-based-buffer-overflow-in-windows-iscsi-allows-an)
- [Microsoft Windows iSCSI use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-70038-use-after-free-in-windows-iscsi-allows-an-unauthorized-attacker)
- [Microsoft Windows iSCSI out-of-bounds write](https://junglewise.ai/threats/cve-2026-69705-out-of-bounds-write-in-windows-iscsi-allows-an-unauthorized)
- [Microsoft Windows iSCSI information disclosure](https://junglewise.ai/threats/cve-2026-69644-exposure-of-sensitive-system-information-to-an-unauthorized)