Cyber Resilience

CVE-2026-4212

Memory Safety in Dlink Dnr-202L Firmware ≤ 2026-02-05

Public PoCMemory Safety
Published
16 March 2026
Modified
19 March 2026
Patch / advisory
CVSS Score v4 7.4
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/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 0.0079 53th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2026-4212 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Dnr-202L Firmware. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 47% 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-2026-4212 is a stack-based buffer overflow vulnerability (associated with CWE-119, CWE-121, and CWE-787) in the Downloads_Schedule_Info function of the /cgi-bin/download_mgr.cgi script. It affects multiple D-Link NAS devices running firmware up to version 20260205, specifically the models DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05, and DNS-1550-04. The issue was published on 2026-03-16 and carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

The vulnerability enables remote exploitation by low-privileged users (PR:L) over the network with low complexity and no user interaction required. Attackers can trigger the buffer overflow via crafted manipulation of the affected function, potentially achieving high-impact compromise of confidentiality, integrity, and availability, such as arbitrary code execution or system crashes on vulnerable devices.

Advisories on VulDB (ctiid.351123, id.351123, submit.770442) document the vulnerability details, while a GitHub repository (https://github.com/wudipjq/my_vuln/blob/main/D-Link8/vuln_161/161.md) publicly discloses an exploit that may be used in attacks. Practitioners should monitor the D-Link website (https://www.dlink.com/) for firmware updates or mitigation guidance.

The exploit has been publicly disclosed, increasing the risk of active exploitation against unpatched D-Link NAS devices.

EU & UK References

Vulnerability Data

A security vulnerability has been detected in D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 and DNS-1550-04 up to 20260205. This affects the function Downloads_Schedule_Info of the file…

more

/cgi-bin/download_mgr.cgi. Such manipulation leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed publicly 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.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
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-2026-4213Same product: Dlink Dnr-202L
CVE-2026-5213Same product: Dlink Dnr-202L
CVE-2026-5211Same product: Dlink Dnr-202L
CVE-2026-5212Same product: Dlink Dnr-202L
CVE-2026-4211Same product: Dlink Dnr-202L
CVE-2026-4214Same product: Dlink Dnr-202L
CVE-2026-5214Same product: Dlink Dnr-202L
CVE-2025-4843Same vendor: Dlink
CVE-2026-4183Same vendor: Dlink
CVE-2025-9938Same vendor: Dlink

Affected Assets

dlink
dnr-202l firmware
≤ 2026-02-05
dlink
dnr-326 firmware
≤ 2026-02-05
dlink
dns-1100-4 firmware
≤ 2026-02-05
dlink
dns-120 firmware
≤ 2026-02-05
dlink
dns-1200-05 firmware
≤ 2026-02-05
dlink
dns-1550-04 firmware
≤ 2026-02-05
dlink
dns-315l firmware
≤ 2026-02-05
dlink
dns-320 firmware
≤ 2026-02-05
dlink
dns-320l firmware
≤ 2026-02-05
dlink
dns-320lw firmware
≤ 2026-02-05
+10 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V17.3.2

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and analysis can discover stack-buffer overflows before deployment.

Input validation directly stops untrusted data from exceeding stack buffer bounds.

Memory-protection mechanisms limit the ability to execute injected code after a stack overflow.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

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

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.

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.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. prevents CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121

References