CVE-2026-3679
Published: 07 March 2026
Summary
CVE-2026-3679 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda F451 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 43.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2026-3679 is a stack-based buffer overflow vulnerability affecting the Tenda FH451 router on firmware version 1.0.0.9. The flaw exists in the formQuickIndex function within the /goform/QuickIndex file, where manipulation of the mit_linktype/PPPOEPassword argument triggers the overflow. It is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow).
The vulnerability 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), indicating it is exploitable remotely over the network with low attack complexity by users possessing low privileges, without requiring user interaction and with unchanged scope. Successful exploitation could result in high impacts to confidentiality, integrity, and availability, potentially allowing arbitrary code execution on the affected device.
References include a public exploit on GitHub at https://github.com/Litengzheng/vul_db/blob/main/FH451/vul_63/README.md, VulDB entries at https://vuldb.com/?ctiid.349581, https://vuldb.com/?id.349581, and https://vuldb.com/?submit.765331, as well as the vendor site at https://www.tenda.com.cn/. The exploit is publicly available and might be used, though no specific patch or mitigation details are outlined in the provided information.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10194
Vulnerability details
A vulnerability was identified in Tenda FH451 1.0.0.9. Affected by this vulnerability is the function formQuickIndex of the file /goform/QuickIndex. Such manipulation of the argument mit_linktype/PPPOEPassword leads to stack-based buffer overflow. It is possible to launch the attack remotely. The…
more
exploit is publicly available and might be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in public web form (/goform/QuickIndex) allows remote low-privileged authenticated attackers to achieve arbitrary code execution on the router, directly enabling T1190 (Exploit Public-Facing Application) for initial compromise and T1068 (Exploitation for Privilege Escalation) from web UI low-priv context to full system control.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SI-2 Flaw Remediation requires applying vendor patches or firmware updates to fix the stack-based buffer overflow in the formQuickIndex function, directly eliminating the vulnerability to remote exploitation.
SI-10 Information Input Validation enforces bounds and format checks on the mit_linktype/PPPOEPassword argument to prevent stack buffer overflows in the /goform/QuickIndex endpoint.
SI-16 Memory Protection deploys stack canaries, ASLR, or DEP to block arbitrary code execution from the buffer overflow even if oversized input reaches the vulnerable function.