# CVE-2026-93652: µD3TN integer overflow in TCPCLv3 handshake heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-93652-d3tn-integer-overflow-in-tcpclv3-handshake-heap-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-93652 · Severity: high · CVSS 7.5 · Published 2026-09-18

µD3TN is a delay-tolerant network daemon that implements the Bundle Protocol for intermittent network communications. An integer overflow in the TCPCLv3 connection handshake allows unauthenticated remote attackers to cause a denial of service by crashing the process, potentially disrupting network relay operations and bundle message delivery.

Technologies: [D3TN µD3TN](https://junglewise.ai/threats/technologies/d3tn). Vendors: [D3TN](https://junglewise.ai/threats/vendors/d3tn).

## Quick answers

**Is CVE-2026-93652 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93652 being exploited in the wild.

**How severe is CVE-2026-93652?** High severity, with a CVSS score of 7.5, published 18 September 2026.

**Which products and versions are affected?** D3TN µD3TN v0.15.0 and earlier.

**Is there a fix for CVE-2026-93652?** 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-2026-93652 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-93652?** Check whether you run D3TN µD3TN 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

An integer overflow vulnerability exists in µD3TN's TCPCLv3 handshake implementation where the peer EID (Endpoint Identifier) length field, stored as uint32_t, is incremented by 1 and used as the size argument to malloc(). When a remote client sends UINT32_MAX as the EID length, the expression "peer_eid_len + 1" wraps to zero, causing malloc(0) to be called. The daemon then attempts to write the original full-length data into the zero-sized allocation via recv(), triggering a heap buffer overflow. This occurs during the initial unauthenticated handshake, allowing any network-reachable attacker to reliably crash the process. The vulnerability has existed since at least the 0.8.0 import in 2020.

## Affected products

- D3TN µD3TN v0.15.0 and earlier

## Timeline

- 2026-09-18: disclosed

## References

- [https://gitlab.com/d3tn/ud3tn/-/work_items/287](https://gitlab.com/d3tn/ud3tn/-/work_items/287)

## Related threats

- [µD3TN SPP parser off-by-one heap overflow](https://junglewise.ai/threats/cve-2026-121513-off-by-one-heap-overflow-in-d3tn-v0-15-1-spp-parser-allows)
- [µD3TN memory leak with amplification in BPv6 EID reference handling](https://junglewise.ai/threats/cve-2026-121512-memory-leak-with-amplification-in-d3tn-bpv6-eid-reference)
- [µD3TN BPv6/BPv7 Fragmenter heap buffer out-of-bounds read](https://junglewise.ai/threats/cve-2026-121511-heap-out-of-bounds-read-in-d3tn-bpv6-bpv7-fragmenter-allows)
- [µD3TN BPv6 heap out-of-bounds write in administrative record parser](https://junglewise.ai/threats/cve-2026-121510-remote-unauthenticated-heap-out-of-bounds-write-in-d3tn-bpv6)
- [µD3TN BPv6 fragmenter use-after-free in cleanup](https://junglewise.ai/threats/cve-2026-121508-use-after-free-in-d3tn-bpv6-fragmenter-cleanup-allows)