CVE-2026-7857
Published: 05 May 2026
Summary
CVE-2026-7857 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Di-8100 Firmware. Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.
Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.
Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.
Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in router web CGI (/user_group.asp) enables remote authenticated RCE on a public-facing network device management interface, directly mapping to exploitation of public-facing applications.
NVD Description
A vulnerability has been found in D-Link DI-8100 16.07.26A1. This vulnerability affects the function sprintf of the file /user_group.asp of the component CGI Handler. The manipulation leads to buffer overflow. The attack may be initiated remotely. The exploit has been…
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disclosed to the public and may be used.
Deeper analysisAI
CVE-2026-7857 is a buffer overflow vulnerability in the D-Link DI-8100 router, specifically affecting firmware version 16.07.26A1. The flaw exists in the sprintf function within the /user_group.asp file of the CGI Handler component, where improper input handling leads to a buffer overflow.
The vulnerability is remotely exploitable over the network with low attack complexity and no user interaction required, but it demands high privileges (PR:H) from the attacker. Per its CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H), successful exploitation can result in high impacts to confidentiality, integrity, and availability, potentially enabling arbitrary code execution or full device compromise by a privileged remote adversary.
Advisories and references, including a detailed GitHub report at https://github.com/draw-ctf/report/blob/main/DI-8100/user_group_asp_overflow.md and VulDB entries at https://vuldb.com/vuln/361134, document the issue and public exploit disclosure. The D-Link website at https://www.dlink.com/ is listed among references, though no specific patches or mitigations are outlined in the available details.
The exploit has been publicly disclosed and may be used, as noted in vulnerability feeds. It maps to CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-120 (Buffer Copy without Checking Size of Input).
Details
- CWE(s)