CVE-2026-5611
Memory Safety in Belkin F9K1015 Firmware 1.00.10
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-2026-5611 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Belkin F9K1015 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-2026-5611 is a stack-based buffer overflow vulnerability in the Belkin F9K1015 router running firmware version 1.00.10. The issue resides in the formCrossBandSwitch function within the /goform/formCrossBandSwitch file, where manipulation of the "webpage" argument triggers the overflow. Associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow), it carries 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), indicating high severity due to its potential for remote exploitation.
Attackers with low privileges (PR:L), such as authenticated users on the network, can exploit this remotely over the network with low complexity and no user interaction required. Successful exploitation grants high-impact confidentiality, integrity, and availability violations, potentially allowing arbitrary code execution, data theft, or device compromise. A public exploit is available, increasing the risk of widespread abuse.
VulDB advisories (e.g., vuln/355402) document the issue, noting early vendor contact with no response or patch issued. Practitioners should reference provided URLs like https://vuldb.com/vuln/355402 for CTI details and https://github.com/Litengzheng/vuldb_new/blob/main/Belkin%20F9K1015/vul_5/README.md for exploit information; mitigation relies on isolating affected devices, restricting access to the /goform endpoint, or upgrading firmware if available from Belkin.
The exploit's public disclosure heightens urgency for Belkin F9K1015 users, as no vendor remediation has been confirmed.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19152
Vulnerability Data
A vulnerability was found in Belkin F9K1015 1.00.10. This affects the function formCrossBandSwitch of the file /goform/formCrossBandSwitch. Performing a manipulation of the argument webpage results in stack-based buffer overflow. The attack can be initiated remotely. The exploit has been made…
more
public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
- 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.
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