# CVE-2026-88357: ntop nDPI unaligned pointer dereference in DNS dissector and serializer

Source: https://junglewise.ai/threats/cve-2026-88357-ndpi-5-1-0-contains-a-memory-access-issue-in-the-dns-dissector  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-24. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-88357 · Severity: high · CVSS 7.5 · Published 2026-09-24

nDPI is a network traffic classification library used for identifying application protocols in packets. Specially crafted DNS packets or serialized data can trigger unaligned memory access in the DNS parser and serialization code, causing the application to crash on certain hardware architectures or when running with strict alignment checking, resulting in denial of service.

Technologies: [Ntop nDPI](https://junglewise.ai/threats/technologies/ndpi). Vendors: [Ntop](https://junglewise.ai/threats/vendors/ntop).

## Quick answers

**Is CVE-2026-88357 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-88357 being exploited in the wild.

**How severe is CVE-2026-88357?** High severity, with a CVSS score of 7.5, published 24 September 2026.

**Which products and versions are affected?** Ntop nDPI 5.1.0.

**Is there a fix for CVE-2026-88357?** A patch was published on 2026-08-31. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-88357 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-88357?** Check whether you run Ntop nDPI 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 stems from casting byte buffer pointers directly to multi-byte integer pointers (16-bit, 32-bit, 64-bit) and dereferencing them without verifying alignment constraints. When the byte offset is odd or misaligned, this violates C alignment rules and triggers UBSan traps, SIGILL signals, or undefined behavior on strict-alignment architectures. The issue affects DNS parsing (get16 operations) and serializer deserialization code; no authentication or user interaction is required, only network-accessible packet input.

## Affected products

- ntop nDPI 5.1.0

## Timeline

- 2026-09-24: disclosed
- 2026-08-31: patched

## References

- [https://github.com/ntop/nDPI/issues/3213](https://github.com/ntop/nDPI/issues/3213)
- [https://github.com/ntop/nDPI/pull/3231](https://github.com/ntop/nDPI/pull/3231)

## Related threats

- [ntop nDPI out-of-bounds read in SoftEther dissector](https://junglewise.ai/threats/cve-2026-116744-ntop-ndpi-through-6-0-contains-an-out-of-bounds-read)
- [ntop nDPI heap buffer overflow in ndpi_json_string_escape](https://junglewise.ai/threats/cve-2026-86098-ntop-ndpi-heap-buffer-overflow-in-ndpi-json-string-escape)