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CVE-2026-7422
MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing
High7.1EPSS 0.18%
- Published
- Updated
- Reserved
- Assigned by
- AMZN
Description
Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, because the loopback detection mechanism skips all input validation for packets whose source MAC matches a local endpoint. To mitigate this issue, users should upgrade to the fixed version when available.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| AMZNCNA (assigner) | 4.0 | High7.1 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| AMZNCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Analyzed | 4.0 | High7.1 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/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 |
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Weakness
Affected products
- affected 4.0.0 – < 4.2.6
- affected 4.3.0 – < 4.4.1
- unaffected 4.2.6
- unaffected 4.4.1
References (4)
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1 (opens in a new tab)patch
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6 (opens in a new tab)patch
- https://aws.amazon.com/security/security-bulletins/2026-021-aws/ (opens in a new tab)vendor-advisory
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9 (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-7422)Record last updated .