CVE-2026-5042: Belkin F9K1122 · Stack-based Buffer Overflow
Affects Belkin F9K1122Source CVE Database V5
Public exploit available · CVSS 8.7 High.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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:PExploitation evidence
Disclosed: evidence found.
CVE published 29 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| BelkinF9K1122 | Affected
| Fixed in– |
AI-suggested
Since the vendor has not responded or released a fix, users should consider mitigating exposure by restricting remote access to the device's management interface, disabling vulnerable features if possible, or replacing the device with a non-affected model until an official patch is available.
Description
CVE-2026-5042 is a high-severity stack-based buffer overflow vulnerability in the Belkin F9K1122 router firmware version 1.00.33. The flaw exists in the formCrossBandSwitch function within the Parameter Handler component, where improper handling of the 'webpage' argument can lead to memory corruption. This vulnerability can be exploited remotely without user interaction. Although the exploit code has been publicly released, there is no indication that the vendor has responded or provided a patch. The vulnerability has a CVSS 4.0 base score of 8.7, indicating a significant risk if exploited.