# CVE-2026-86509: D-Link DIR-895L stack-based buffer overflow in udhcpcd

Source: https://junglewise.ai/threats/cve-2026-86509-d-link-dir-895l-stack-based-buffer-overflow-in-udhcpcd  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-86509 · Severity: critical · CVSS 9.6 · Published 2026-09-08

D-Link DIR-895L is a wireless router used to provide internet connectivity in homes and small businesses. A stack-based buffer overflow in the DHCP server component (udhcpcd) can be exploited by an attacker on the local network to crash the device or execute arbitrary code, potentially compromising network security and disrupting service availability.

Technologies: [D-Link DIR-895L](https://junglewise.ai/threats/technologies/dir-895l). Vendors: [D-Link](https://junglewise.ai/threats/vendors/d-link).

## Quick answers

**Is CVE-2026-86509 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86509 being exploited in the wild.

**How severe is CVE-2026-86509?** Critical severity, with a CVSS score of 9.6, published 8 September 2026.

**Which products and versions are affected?** D-Link DIR-895L A1_102b07.

**Is there a fix for CVE-2026-86509?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86509 attacked?** It is attacked from the adjacent network.

**Am I affected by CVE-2026-86509?** Check whether you run D-Link DIR-895L at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a stack-based buffer overflow in the sendOffer/sendACK functions within udhcpcd/serverpacket.c of the D-Link DIR-895L A1_102b07 firmware. The flaw is triggered during the parsing of DHCP Option 125 (TR-111) in DHCP server responses. An attacker on the local network can craft a malicious DHCP packet to overflow the stack buffer, potentially enabling code execution or denial of service. The attack requires network access to the DHCP server and does not require authentication. Public exploits have been released.

## Affected products

- D-Link DIR-895L A1_102b07

## Timeline

- 2026-09-08: disclosed
- other: Public exploit available

## References

- [https://tzh00203.notion.site/D-Link-DIR-895L-Stack-Overflow-in-udhcpd-TR-111-Option-125-Parsing-33cb5c52018a80dc8140e1502e4814d0](https://tzh00203.notion.site/D-Link-DIR-895L-Stack-Overflow-in-udhcpd-TR-111-Option-125-Parsing-33cb5c52018a80dc8140e1502e4814d0)
- [https://vuldb.com/cve/CVE-2026-86509](https://vuldb.com/cve/CVE-2026-86509)

## Related threats

- [D-Link DIR-895L out-of-bounds write in L2TP parser](https://junglewise.ai/threats/cve-2026-100740-a-vulnerability-was-detected-in-d-link-dir-895l-a1-102b07)
- [D-Link DIR-895L command injection in udhcpcd sendACK](https://junglewise.ai/threats/cve-2026-86295-d-link-dir-895l-command-injection-in-udhcpcd-sendack)