What is the CVSS score of CVE-2026-51380?

CVE-2026-51380 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

Which versions of Tenda AC10 are affected by CVE-2026-51380?

Tenda AC10 v3 routers (firmware V03.03.16.09) contain a critical buffer overflow vulnerability with publicly available proof-of-concept code enabling remote code execution or permanent device failure…

How to fix or mitigate CVE-2026-51380?

Within 24 hours, inventory all Tenda AC10 v3 devices running firmware V03.03.16.09 and map their network exposure. Within 7 days, immediately restrict access to the management interface through firewall rules and network segmentation, allowing administrative connections only from trusted IP ranges and disabling remote management if operationally feasible. Within 30 days, establish continuous monitoring of Tenda's security advisories for patch availability; prepare a firmware upgrade plan to deploy immediately upon patch release, or initiate vendor evaluation and replacement planning if remediation cannot be timely.

Tenda AC10 CVE-2026-51380

CRITICAL

Classic Buffer Overflow (CWE-120)

2026-07-15 mitre

Buffer Overflow Tenda Denial Of Service N A

9.8

CVSS 3.1 · Vendor: mitre

Severity by source

Vendor (mitre) PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

vuln.today AI

9.8 CRITICAL

Unauthenticated, low-complexity request to a network-reachable CGI endpoint; A:H is certain for permanent DoS and C:H/I:H reflect the credible RCE potential from a control-flow overflow.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (mitre).

CVSS VectorVendor: mitre

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Jul 16, 2026 - 16:23 vuln.today

CVSS changed

Jul 16, 2026 - 16:22 NVD

9.8 (CRITICAL)

CVE Published

Jul 15, 2026 - 00:00 cve.org

UNKNOWN (no severity yet)

CVE Published

Jul 15, 2026 - 00:00 cve.org

CRITICAL 9.8

DescriptionCVE.org

Buffer Overflow vulnerability in Tenda AC10 v3 (firmware V03.03.16.09) allows attackers to cause a permanent Denial of Service (DoS) or potentially execute remote code via the /cgi-bin/UploadCfg endpoint

AnalysisAI

Remote code execution or permanent denial of service in the Tenda AC10 v3 SOHO router (firmware V03.03.16.09) stems from a classic buffer overflow reachable through the /cgi-bin/UploadCfg web endpoint. Attackers who can reach the router's management interface can send oversized crafted input to crash the device permanently or potentially run arbitrary code on it. Proof-of-concept material appears to be published on GitHub, though this is not listed in CISA KEV and carries a low EPSS score of 0.17% (7th percentile), indicating no confirmed widespread exploitation yet.

Technical ContextAI

The Tenda AC10 is an AC1200 dual-band consumer/SOHO Wi-Fi router. The flaw is a CWE-120 Classic Buffer Overflow, meaning the firmware copies attacker-controlled input into a fixed-size stack or heap buffer without validating its length, corrupting adjacent memory. The vulnerable code path is the CGI handler behind /cgi-bin/UploadCfg, which processes configuration-upload requests to the router's embedded httpd web server. On memory-constrained MIPS/ARM embedded devices like this, such overflows readily crash the httpd/router process (DoS) and, if the overwritten memory includes control data such as a return address, can be leveraged for arbitrary code execution. CPE data in the feed is a placeholder (cpe:2.3:a:n/a:n/a:*) and does not properly identify the product, so the description and vendor material are the authoritative source for affected identification.

RemediationAI

No vendor-released patched firmware version is identified in the provided data, so no fixed version can be cited; monitor the Tenda support page at https://www.tendacn.com/material/show/104968 for an updated firmware release and apply it once available. As compensating controls, disable remote/WAN management on the router so the web interface and the /cgi-bin/UploadCfg endpoint are only reachable from the trusted LAN (trade-off: administrators lose remote administration convenience). Restrict access to the router's HTTP/HTTPS management ports to a limited set of trusted management hosts via firewall/ACL where the platform allows, and change default credentials to reduce lateral access. If the model reaches end-of-support without a fix, plan replacement with a supported device, since embedded routers rarely receive backported security fixes.