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.

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

EPSS: 0.003 (22.8th percentile) — read the EPSS interpretation.

Affected products

Amazon Freertos — versions 2.3.4

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

mbanyamer/CVE-2025-5688-FreeRTOS-Plus-TCP-Out-of-Bounds-Write

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)

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.