What is the CVSS score of CVE-2026-2191?

CVE-2026-2191 has a CVSS 3.1 base score of 7.2 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Ac9 Firmware are affected by CVE-2026-2191?

A high-severity vulnerability in Tenda AC9 routers (CVE-2026-2191) allows remote attackers to exploit the DDoS defense function with a CVSS score of 7.2.

Is there a public PoC exploit available for CVE-2026-2191?

Yes, a public proof-of-concept exploit is available for CVE-2026-2191. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-2191?

Within 24 hours: Inventory all Tenda AC9 15.03.06.42_multi devices in your network and isolate or restrict external access to affected units. Within 7 days: Implement network segmentation to limit lateral movement if a device is compromised, and disable the DDoS defense feature if operationally feasible. Within 30 days: Contact Tenda for patch availability and develop a replacement strategy for affected devices, prioritizing units exposed to untrusted networks.

Ac9 Firmware CVE-2026-2191

HIGH

Buffer Overflow (CWE-119)

2026-02-08 cna@vuldb.com

Buffer Overflow Stack Overflow Ac9 Firmware

7.2

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.2 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Feb 10, 2026 - 15:09 vuln.today

Public exploit code

CVE Published

Feb 08, 2026 - 23:15 nvd

HIGH 7.2

DescriptionCVE.org

A weakness has been identified in Tenda AC9 15.03.06.42_multi. Affected is the function formGetDdosDefenceList. This manipulation of the argument security.ddos.map causes stack-based buffer overflow. The attack may be initiated remotely. The exploit has been made available to the public and could be used for attacks.

AnalysisAI

Stack overflow in Tenda AC9 firmware versions up to 15.03.06.42_multi allows remote attackers with high privileges to achieve complete system compromise through manipulation of the security.ddos.map parameter. Public exploit code exists for this vulnerability, increasing exploitation risk. No patch is currently available.

Technical ContextAI

Classified as CWE-119 (Buffer Overflow). Affects Ac9 Firmware. A weakness has been identified in Tenda AC9 15.03.06.42_multi. Affected is the function formGetDdosDefenceList. This manipulation of the argument security.ddos.map causes stack-based buffer overflow. The attack may be initiated remotely. The exploit has been made available to the public and could be used for attacks.

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible. Restrict network access to the affected service where possible.