High severity · published Aug 14, 2026
CVE-2026-19811
TOTOLINK A800R firewall.so cstecgi.cgi setIpQosRules stack-based overflow
8.8
CVSS
0.9%
EPSS
No
On KEV
Description
A security flaw has been discovered in TOTOLINK A800R 4.1.2cu.5137_B20200730. The impacted element is the function setIpQosRules of the file /cgi-bin/cstecgi.cgi of the component firewall.so. The manipulation of the argument Comment results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 58% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
A8
A800R · TOTOLINK
4.1.2cu.5137_B20200730 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-19811
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-19811
github.com
https://github.com/panda666-888/vuls/blob/main/totolink/a800r/setIpQosRules.md
vuldb.com
https://vuldb.com/cve/CVE-2026-19811
vuldb.com
https://vuldb.com/submit/869425
vuldb.com
https://vuldb.com/vuln/389947
vuldb.com
https://vuldb.com/vuln/389947/cti
www.totolink.net
https://www.totolink.net/
More from A800R
9.8
CVE-2025-4496
TOTOLINK T10/A3100R/A950RG/A800R/N600R/A3000RU/A810R cstecgi.cgi CloudACMunualUpdate buffer overflow
9.8
CVE-2025-28034
TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R V4.1.2cu.5182_B20201102, A950RG V4.1.2cu.5161_B20200903, A3000RU V5.9c.5185_B20201128, and A3100R…
9.8
CVE-2025-28036
TOTOLINK A950RG V4.1.2cu.5161_B20200903 was found to contain a pre-auth remote command execution vulnerability in the setNoticeCfg function through the NoticeUrl parameter
9.8
CVE-2025-28035
TOTOLINK A830R V4.1.2cu.5182_B20201102 was found to contain a pre-auth remote command execution vulnerability in the setNoticeCfg function through the NoticeUrl parameter
9.8
CVE-2025-28138
The TOTOLINK A800R V4.1.2cu.5137_B20200730 were found to contain a pre-auth remote command execution vulnerability in the setNoticeCfg function through the NoticeUrl parameter