# CVE-2026-7854: D-Link DI-8100 buffer overflow in url_rule.asp

Source: https://junglewise.ai/threats/cve-2026-7854-d-link-di-8100-buffer-overflow-in-url-rule-asp  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-05. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-7854 · Severity: critical · CVSS 9.8 · Published 2026-05-05

A security vulnerability has been identified in the D-Link DI-8100, a router used for managing business and home network traffic. An attacker can exploit this flaw to crash the device or potentially take control of it by sending specially crafted web requests. This could lead to a total loss of internet connectivity for the office or home, and may allow unauthorized access to the device's management settings.

Technologies: [Dlink Di-8100](https://junglewise.ai/threats/technologies/di-8100), [Dlink Di-8100 Firmware](https://junglewise.ai/threats/technologies/di-8100-firmware). Vendors: [Dlink](https://junglewise.ai/threats/vendors/dlink).

## Quick answers

**Is CVE-2026-7854 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-7854 being exploited in the wild.

**How severe is CVE-2026-7854?** Critical severity, with a CVSS score of 9.8, published 5 May 2026.

**Which products and versions are affected?** D-Link DI-8100 Gigabit Router 16.07.26A1.

**Is there a fix for CVE-2026-7854?** 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-2026-7854 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-7854?** 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 exists in the D-Link DI-8100 Gigabit Router firmware version 16.07.26A1. The vulnerability is located in the 'url_rule_asp' function (at address 0x00481784) within the '/url_rule.asp' component. The root cause is the improper use of 'sprintf' to concatenate user-supplied POST parameters (such as 'name', 'ips', and 'time') into a fixed-size stack buffer of only 8 bytes without bounds checking. A remote attacker can exploit this by sending a crafted HTTP POST request to the web management interface, leading to memory corruption, denial-of-service (DoS), or potential remote code execution. Public exploit code has been disclosed.

## Affected products

- D-Link DI-8100 Gigabit Router 16.07.26A1

## Timeline

- 2026-05-05: disclosed: Initial disclosure via VulDB and NVD
- 2026-05-05: advisory

## References

- [https://github.com/draw-ctf/report/blob/main/DI-8100/url_rule_asp_overflow.md](https://github.com/draw-ctf/report/blob/main/DI-8100/url_rule_asp_overflow.md)
- [https://vuldb.com/submit/807838](https://vuldb.com/submit/807838)
- [https://vuldb.com/vuln/361131](https://vuldb.com/vuln/361131)
- [https://vuldb.com/vuln/361131/cti](https://vuldb.com/vuln/361131/cti)
- [https://www.dlink.com/](https://www.dlink.com/)

## Related threats

- [D-Link DI-8100 buffer overflow in user_group.asp CGI handler](https://junglewise.ai/threats/cve-2026-7857-d-link-di-8100-buffer-overflow-in-user-group-asp-cgi-handler)
- [D-Link DI-8100 stack buffer overflow in url_member.asp](https://junglewise.ai/threats/cve-2026-7856-d-link-di-8100-stack-buffer-overflow-in-url-member-asp)
- [D-Link DI-8100 buffer overflow in tggl_asp function](https://junglewise.ai/threats/cve-2026-7855-d-link-di-8100-buffer-overflow-in-tggl-asp-function)
- [D-Link DI-8100 buffer overflow in /auto_reboot.asp](https://junglewise.ai/threats/cve-2026-7853-d-link-di-8100-buffer-overflow-in-auto-reboot-asp)
- [D-Link DI-8100 stack-based buffer overflow in yyxz.asp](https://junglewise.ai/threats/cve-2026-7851-d-link-di-8100-stack-based-buffer-overflow-in-yyxz-asp)