Buffer overflow in Amazon Freertos

CVE-2025-5688

We have identified a buffer overflow issue allowing out-of-bounds write when processing LLMNR or mDNS queries with very long DNS names. This issue only affects systems using Buffer Allocation Scheme 1 with LLMNR or mDNS enabled. Users should upgrade to the latest version and ensure any forked or derivative code is patched to incorporate the new fixes.

Vulnerability class: Buffer Overflow

Published · last modified .

EPSS exploit prediction

EPSS: 0.004 (26.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-5688: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-5688?
CVE-2025-5688 is a vulnerability in Amazon Freertos, classified under Out-of-bounds Write. Published 2025-06-04.
Is CVE-2025-5688 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.