Cyber Posture

CVE-2026-5830

HighPublic PoC

Published: 09 April 2026

Published
09 April 2026
Modified
30 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0008 23.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5830 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac15 Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 23.9th 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).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the stack-based buffer overflow by requiring timely testing and installation of firmware patches for the affected Tenda AC15 device.

prevent

Prevents exploitation of the buffer overflow in websGetVar by validating and restricting the length/content of oldPwd, newPwd, and cfmPwd inputs.

prevent

Mitigates stack-based buffer overflow impacts through memory protection mechanisms like stack canaries, ASLR, and non-executable stacks.

MITRE ATT&CK Enterprise TechniquesAI

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.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

Buffer overflow in public-facing web interface (/goform/SysToolChangePwd) enables remote authenticated exploitation for arbitrary code execution on Linux-based router, directly mapping to T1190 and facilitating T1059.004.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A vulnerability was identified in Tenda AC15 15.03.05.18. This affects the function websGetVar of the file /goform/SysToolChangePwd. Such manipulation of the argument oldPwd/newPwd/cfmPwd leads to stack-based buffer overflow. The attack can be executed remotely. The exploit is publicly available and…

more

might be used.

Deeper analysisAI

CVE-2026-5830 is a stack-based buffer overflow vulnerability affecting the Tenda AC15 router on firmware version 15.03.05.18. The flaw exists in the websGetVar function of the /goform/SysToolChangePwd file, where manipulation of the oldPwd, newPwd, or cfmPwd arguments triggers the overflow. Published on 2026-04-09, it 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) and maps to CWEs 119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and 121 (Stack-based Buffer Overflow).

The vulnerability enables remote exploitation by attackers with low privileges, such as authenticated users on the device. By sending crafted requests to the affected endpoint, an attacker can overflow the stack, potentially leading to arbitrary code execution and high-impact compromise of confidentiality, integrity, and availability.

Advisories on VulDB (https://vuldb.com/vuln/356277, https://vuldb.com/vuln/356277/cti, https://vuldb.com/submit/789178) document the issue and related CTI. The Tenda vendor site (https://www.tenda.com.cn/) is referenced for potential firmware updates or guidance.

A public exploit is available at https://files.catbox.moe/xrk8jb.zip, heightening the risk of real-world attacks against unpatched Tenda AC15 devices.

Details

CWE(s)

Affected Products

tenda
ac15 firmware
15.03.05.18

CVEs Like This One

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CVE-2025-0566Same product: Tenda Ac15
CVE-2026-3400Same product: Tenda Ac15
CVE-2026-4975Same product: Tenda Ac15
CVE-2026-24101Same product: Tenda Ac15
CVE-2026-24103Same product: Tenda Ac15
CVE-2025-25632Same product: Tenda Ac15

References