CVE-2026-6157
Published: 13 April 2026
Summary
CVE-2026-6157 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Totolink A800R (inferred from references). 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 37.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2026-6157 is a buffer overflow vulnerability in the Totolink A800R router firmware version 4.1.2cu.5137_B20200730. The flaw affects the setAppEasyWizardConfig function in the /lib/cste_modules/app.so library, where manipulation of the apcliSsid argument triggers the overflow. It is classified under CWE-119 and CWE-120, with 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 an attacker possessing low privileges, with low attack complexity and no requirement for user interaction. Successful exploitation can result in high impacts to confidentiality, integrity, and availability, potentially allowing arbitrary code execution on the affected device.
Advisories and references include a public proof-of-concept exploit on GitHub (https://github.com/xyh4ck/iot_poc/blob/main/TOTOLINK/A800R/01_Buffer_Overflow_setAppEasyWizardConfig.md) and details from VulDB (https://vuldb.com/vuln/357037, https://vuldb.com/submit/793114, https://vuldb.com/vuln/357037/cti). The vendor website is available at https://www.totolink.net/. The exploit is public and may be used, as noted in the disclosure published on 2026-04-13.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21814
Vulnerability details
A vulnerability was detected in Totolink A800R 4.1.2cu.5137_B20200730. This impacts the function setAppEasyWizardConfig in the library /lib/cste_modules/app.so. The manipulation of the argument apcliSsid results in buffer overflow. The attack can be executed remotely. The exploit is now public and may…
more
be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in public-facing router firmware configuration function (setAppEasyWizardConfig) directly enables remote code execution by exploiting a vulnerable public-facing application.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Validating the length and format of the apcliSsid argument in setAppEasyWizardConfig directly prevents the buffer overflow triggered by oversized input.
Memory protection mechanisms such as stack canaries, ASLR, and DEP mitigate arbitrary code execution even if the buffer overflow in app.so occurs.
Timely flaw remediation through firmware patching eliminates the specific buffer overflow vulnerability in Totolink A800R version 4.1.2cu.5137_B20200730.