Fast DDS is a C++ implementation of the DDS (Data Distribution Service) standard of the OMG (Object Management Group ). Prior to versions 3.4.1, 3.3.1, and 2.6.11, a remotely triggerable Out-of-Memory (OOM) denial-of-service exists in Fast -DDS when processing RTPS GAP submessages under RELIABLE QoS. By sending a tiny GAP packet with a huge gap range (`gapList .base - gapStart`), an attacker drives `StatefulReader::processGapMsg()` into an unbounded loop that inserts millions of s equence numbers into `WriterProxy::changes_received_` (`std::set`), causing multi-GB heap growth and process termination. No authentication is required beyond network reachability to the reader on the DDS domain. In environments without an RSS limit (non-ASan / unlimited), memory consumption was observed to rise to ~64 GB. Versions 3.4.1, 3.3.1, and 2.6.11 patch t he issue.
Conclusion & alert: CVE-2025-64438 is rated Low Risk (9.1/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-02-04 | — | 0.03% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 1.7 | 4.0 | LOW |
|
— | — | [email protected] |
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-64438 not yet assigned priority: Debian including 1 source packages (fastdds), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. | https://security-tracker.debian.org/tracker/CVE-2025-64438 |
ubuntu
|
medium | CVE-2025-64438 medium priority: Ubuntu including 1 source packages (fastdds), 5 status rows across 5 suites (jammy, noble, plucky, questing, upstream): needs-triage 4, ignored 1. | https://ubuntu.com/security/CVE-2025-64438 |