Is CVE-2026-7857 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-7857 being exploited in the wild.

How severe is CVE-2026-7857?

High severity, with a CVSS score of 7.2, published 5 May 2026.

Is there a fix for CVE-2026-7857?

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-2026-7857 attacked?

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

Am I affected by CVE-2026-7857?

Check whether you run Dlink Di-8100 or Dlink Di-8100 Firmware. 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-2026-7857: D-Link DI-8100 buffer overflow in user_group.asp CGI handler

CVE-2026-7857 · Severity: high · CVSS 7.2 · Published 2026-05-05

A security vulnerability exists in the D-Link DI-8100 enterprise router. An attacker with administrative access can send a specially crafted request to the device's management interface to cause a system crash or potentially take full control of the hardware. This could lead to a total disruption of network services or unauthorized access to internal traffic.

Technologies: Dlink Di-8100, Dlink Di-8100 Firmware. Vendors: Dlink.

Quick answers

Is CVE-2026-7857 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-7857 being exploited in the wild.
How severe is CVE-2026-7857?: High severity, with a CVSS score of 7.2, published 5 May 2026.
Which products and versions are affected?: D-Link DI-8100 16.07.26A1.
Is there a fix for CVE-2026-7857?: 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-2026-7857 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-7857?: Check whether you run Dlink Di-8100 or Dlink Di-8100 Firmware. 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 vulnerability exists in the CGI handler of D-Link DI-8100 firmware version 16.07.26A1. The flaw is located in the processing of the /user_group.asp endpoint, specifically within a function that utilizes the unsafe 'sprintf' function to concatenate user-supplied parameters (such as 'attr', 'name', 'mem', and 'pri') into a fixed-size stack buffer without bounds checking. An authenticated attacker can exploit this by sending a crafted HTTP POST request with an oversized string, leading to stack corruption. This can result in a crash of the HTTP service (DoS) or potentially remote code execution (RCE). A public exploit (PoC) has been disclosed.

Affected products

D-Link DI-8100 16.07.26A1

Timeline

2026-05-05: disclosed: Public disclosure of the vulnerability and PoC.
2026-05-05: advisory

References

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