CVE-2026-100740
CRITICALCVE-2026-100740 is a critical-severity (CVSS 9.9) Buffer Overflow vulnerability. No vendor fix is recorded yet; mitigation options are listed below.
A vulnerability was detected in D-Link DIR-895L A1_102b07. Impacted is the function tunnel_set_params of the file tunnel.c of the component L2TP Control Channel Parser. Performing a…
Description
A vulnerability was detected in D-Link DIR-895L A1_102b07. Impacted is the function tunnel_set_params of the file tunnel.c of the component L2TP Control Channel Parser. Performing a manipulation results in out-of-bounds write. The attack may be initiated remotely. The exploit is now public and may be used.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`). Because remote code execution targets the running service rather than your application code, O3 also flags the exploit behaviour from runtime telemetry and egress traffic.
Remediation status
No fixed release is recorded for CVE-2026-100740 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process. O3's runtime protection blocks the buffer overflow flaw at execution, which holds the line on hosts you cannot patch immediately.
How O3 protects you
O3 detects and blocks CVE-2026-100740 exploitation at runtime with eBPF exploit-chain detection, plus L7 egress monitoring that catches a post-exploitation callback and cuts the attacker's outbound channel.
Tailored to CVE-2026-100740. 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-2026-100740 in your dependencies?
O3 Security finds CVE-2026-100740 across dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.