CVE-2026-15548: Shibby Tomato stack overflow in httpd DNS List Rendering

CVE-2026-15548 · Severity: high · CVSS 8.8 · Published 2026-07-13

A security vulnerability exists in the Shibby Tomato router firmware, which is used to manage home and small office network routers. An attacker who can influence the DNS configuration can cause the router's management web service to crash or potentially take control of the device. This could lead to a complete loss of internet connectivity or unauthorized access to the network's administrative interface.

Technologies: Shibby Tomato. Vendors: Shibby.

Quick answers

Is CVE-2026-15548 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-15548 being exploited in the wild.
How severe is CVE-2026-15548?
High severity, with a CVSS score of 8.8, published 13 July 2026.
Which products and versions are affected?
Shibby Tomato up to 1.28.0000.
Is there a fix for CVE-2026-15548?
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-2026-15548 attacked?
It is attacked over the network, in device firmware.
Am I affected by CVE-2026-15548?
Check whether you run Shibby Tomato 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 'httpd' binary of Shibby Tomato firmware (up to version 1.28.0000) within the DNS List Rendering component. The vulnerability is located in function 'sub_407220', where the software allocates a fixed 128-byte stack buffer to store a JavaScript array of DNS server information. The function uses 'sprintf' in a loop to append DNS entries without performing bounds checking. If the number of DNS entries (retrieved via 'get_dns()') is sufficiently large (e.g., 8 or more entries), the resulting string exceeds the 128-byte buffer, leading to a stack overflow. This can be exploited by an authenticated attacker to crash the management service or potentially achieve remote code execution. The Shibby Tomato project is superseded by FreshTomato.

Affected products

  • Shibby Tomato up to 1.28.0000

Timeline

  • 2026-06-10: disclosed: Initial discovery and report by Fengyi Wang
  • 2026-07-13: advisory: CVE published by VulDB/NVD

References

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