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-2026-2871 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda A21 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 49th 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 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-2026-2871 is a stack-based buffer overflow vulnerability affecting the Tenda A21 router on firmware version 1.0.0.0. The flaw exists in the fromSetIpMacBind function within the /goform/SetIpMacBind file, where manipulation of the argument list triggers the overflow. It is associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow).
The vulnerability is remotely exploitable over the network with low attack complexity, requiring low privileges (PR:L) and no user interaction, as indicated by its 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 authenticated attacker with low privileges could exploit it to achieve high impacts on confidentiality, integrity, and availability, potentially leading to arbitrary code execution.
Advisories and additional details are documented in references including VulDB entries (ctiid.347108, id.347108, submit.754630, submit.754631) and a GitHub issue at https://github.com/QIU-DIE/cve-nneeww/issues/2. The exploit has been publicly disclosed and is available for use in attacks, though no specific patch or mitigation steps are outlined in the primary description.
The vulnerability was published on 2026-02-21, with public exploit availability heightening the risk for unpatched Tenda A21 devices.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-7518
Vulnerability Data
A weakness has been identified in Tenda A21 1.0.0.0. This affects the function fromSetIpMacBind of the file /goform/SetIpMacBind. This manipulation of the argument list causes stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit has…
more
been made available to the public and could be used for attacks.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 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.
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 gates can enforce security reviews that catch buffer issues.
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