Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-4961 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac6 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-4961, published on 2026-03-27, is a stack-based buffer overflow vulnerability affecting Tenda AC6 routers running version 15.03.05.16. The flaw exists in the formQuickIndex function of the /goform/QuickIndex file within the POST Request Handler component, where manipulation of the PPPOEPassword argument triggers the overflow. It is classified under CWE-119, CWE-121, and CWE-787, 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).
An attacker with low privileges can exploit this vulnerability remotely over the network with low complexity and no user interaction required. Successful exploitation grants high-impact access to confidentiality, integrity, and availability, potentially allowing arbitrary code execution or denial of service. A public exploit is available and might be used in attacks.
Advisories from VulDB, including details at https://vuldb.com/?ctiid.353838, https://vuldb.com/?id.353838, and https://vuldb.com/?submit.777617, document the issue, while the vendor site at https://www.tenda.com.cn/ provides relevant information. Security practitioners should review these references for patch availability or mitigation guidance.
The public availability of an exploit, as noted in a detailed write-up at https://lavender-bicycle-a5a.notion.site/Tenda-AC6-QuickIndex-32053a41781f80758e27fa4259ec80cf?source=copy_link, elevates the risk for exposed Tenda AC6 devices.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-16724
Vulnerability Data
A vulnerability was identified in Tenda AC6 15.03.05.16. Affected by this vulnerability is the function formQuickIndex of the file /goform/QuickIndex of the component POST Request Handler. The manipulation of the argument PPPOEPassword leads to stack-based buffer overflow. The attack is…
more
possible to be carried out remotely. The exploit is publicly available and might be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 2 hardening rules · 2 OS baselines
V17.3.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can discover stack-buffer overflows before deployment.
Input validation directly stops untrusted data from exceeding stack buffer bounds.
Memory-protection mechanisms limit the ability to execute injected code after a stack overflow.
Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.
Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.
Vulnerability scanning and code analysis directly surface buffer-boundary flaws.
Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.
Developer training on secure coding reduces introduction of memory-buffer errors.
Patching replaces vulnerable code containing buffer-boundary defects.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.
Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.
Application security requirements can specify memory-safety rules, but do not prescribe implementation details.
Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.
Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.
Change management can enforce review gates that catch unsafe memory operations before deployment.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. prevents CWE-121
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121