CVE-2026-85109
CRITICALCVE-2026-85109 is a critical-severity (CVSS 9.8) Buffer Overflow vulnerability. O3 Security confirms whether CVE-2026-85109 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
A vulnerability was determined in Tenda HG10 300001138. This issue affects the function formLogin of the file /boaform/formLogin of the component Boa Web Server. Executing a manipulation…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-85109.
Description
A vulnerability was determined in Tenda HG10 300001138. This issue affects the function formLogin of the file /boaform/formLogin of the component Boa Web Server. Executing a manipulation of the argument Username can lead to buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-85109 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-85109 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-85109. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-85109 in your dependencies?
O3 detects CVE-2026-85109 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.