CVE-2025-5688: AWS FreeRTOS · Out-of-bounds Write
Affects AWS FreeRTOSSource CVE Database V5
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubfreertos/FreeRTOS-Plus-TCPpkg:github/freertos/FreeRTOS-Plus-TCPOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Upgrade all affected Amazon FreeRTOS instances to the latest version that includes the patch for CVE-2025-5688.
- Audit and patch any forks or derivative FreeRTOS codebases used internally or by third-party vendors to ensure the fix is applied.
- Disable LLMNR and mDNS services on devices where these protocols are not required to reduce attack surface.
- Implement network segmentation to isolate IoT and embedded devices from critical network segments, limiting local network exposure.
- Employ strict network access controls and monitoring to detect anomalous LLMNR/mDNS traffic patterns indicative of exploitation attempts.
- Conduct regular firmware and software integrity checks on embedded devices to detect unauthorized modifications.
- Collaborate with device manufacturers and suppliers to ensure timely updates and vulnerability management in embedded products.
Description
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.