Cyber Resilience

CVE-2026-7857

Memory Safety in Dlink Di-8100 Firmware 16.07.26a1

Public PoCMemory Safety
Published
05 May 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 7.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.042 90th percentile
Risk Priority 34 floored blend · peak EPSS

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 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 10% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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).

EU & UK References

Vulnerability Data

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…

more

disclosed to the public and may be used.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-7854Same product: Dlink Di-8100
CVE-2026-7856Same product: Dlink Di-8100
CVE-2025-6881Same product: Dlink Di-8100
CVE-2026-7248Same product: Dlink Di-8100
CVE-2026-7247Same product: Dlink Di-8100
CVE-2026-7855Same product: Dlink Di-8100
CVE-2026-7853Same product: Dlink Di-8100
CVE-2026-7851Same product: Dlink Di-8100
CVE-2025-7762Same product: Dlink Di-8100
CVE-2025-5228Same product: Dlink Di-8100

Affected Assets

dlink
di-8100 firmware
16.07.26a1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V5.2.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and analysis can find missing size checks before deployment.

Input validation directly enforces size checks before buffer copies.

Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.

Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

References