Is CVE-2026-101038 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-101038 being exploited in the wild.

How severe is CVE-2026-101038?

Critical severity, with a CVSS score of 9.9, published 28 September 2026.

Which products and versions are affected?

Fast FAC1200R 5.0_20201119_1.0.2.

Is there a fix for CVE-2026-101038?

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-2026-101038 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-101038?

Check whether you run Fast FAC1200R at an affected version. 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.

CVE-2026-101038: FAST FAC1200R stack buffer overflow in MmtAtePrase

CVE-2026-101038 · Severity: critical · CVSS 9.9 · Published 2026-09-28

The FAST FAC1200R router contains a stack buffer overflow vulnerability in its network-accessible UDP service that parses configuration commands. An attacker on the network can crash the router or potentially gain code execution by sending a specially crafted packet to UDP port 1060, disrupting service availability. The vendor has not provided a patch despite early notification.

Vendors: Fast.

Quick answers

Is CVE-2026-101038 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-101038 being exploited in the wild.
How severe is CVE-2026-101038?: Critical severity, with a CVSS score of 9.9, published 28 September 2026.
Which products and versions are affected?: Fast FAC1200R 5.0_20201119_1.0.2.
Is there a fix for CVE-2026-101038?: 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-2026-101038 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-101038?: Check whether you run Fast FAC1200R at an affected version. 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 stack-based buffer overflow exists in the MmtAtePrase parser component of the twlantask UDP service (port 1060) triggered by oversized "wioctl" command arguments without sufficient bounds checking. The vulnerability requires network access but no authentication; a crafted packet with 3065+ space characters causes stack corruption, leading to denial of service or potential code execution. No vendor patch is currently available.

Affected products

FAST FAC1200R 5.0_20201119_1.0.2

Timeline

2026-09-28: disclosed: Publicly disclosed with proof-of-concept payload on GitHub
2026-09-28: other: Vendor contacted but did not respond

References

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