CVE-2026-102551
CRITICAL 9.2Improper verification of the source of a communication channel in the IPv6 Router Advertisement handler in Amazon FreeRTOS-Plus-TCP before V4.4.2 might allow a remote third-party to influence an endpoint's IPv6 default gateway, on-link prefix, and address configuration via a crafted Router Advertisement. To remediate this issue, users should upgrade to version V4.4.2.
Severe if exploited (CVSS 9.2), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 20th percentile
Impact if exploited
9.2CVSS 4.0 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ⚠Requirements: Specific conditions must be present
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-940: Improper verification of source of a communication channel
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
References and research data (JSON)
All CVSS metrics
- HIGH 7.7 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L - CRITICAL 9.2 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N - CRITICAL 9.2 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 7.7 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
References
Patches & mitigations
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.2 CVE record · AMZN · Updated 2026-10-16T17:30:47.034Z
NVD · CVE-2026-102551 · Updated 2026-10-19T13:16:53.353
Advisories
- https://aws.amazon.com/security/security-bulletins/2026-139-aws/ CVE record · AMZN · Updated 2026-10-16T17:30:47.034Z
NVD · CVE-2026-102551 · Updated 2026-10-19T13:16:53.353 - https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-pjq5-fqrr-g6pv CVE record · AMZN · Updated 2026-10-16T17:30:47.034Z
NVD · CVE-2026-102551 · Updated 2026-10-19T13:16:53.353 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-103021 EUVD · EUVD-2026-103021