Vulnerability Description
A potential out-of-bounds write/read exists in the TLS socket connect path of the network sockets subsystem (subsys/net/lib/sockets/sockets_tls.c). When the TLS session cache is enabled, tls_session_store() and tls_session_restore() memcpy the caller-supplied address into a fixed-size buffer using the caller-controlled addrlen value without validating it against the destination size. struct net_sockaddr is an opaque type, so an application can pass an addrlen larger than sizeof(struct net_sockaddr) (for example 128 bytes into a 24-byte stack buffer), causing the memcpy to read and write past the end of the address memory used by the TLS session cache. This out-of-bounds write can lead to a crash and denial of service, and potentially to arbitrary code execution.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Zephyrproject | Zephyr | <= 4.3.0 |
Related Weaknesses (CWE)
References
- https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-ExploitPatchVendor Advisory
- https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-ExploitPatchVendor Advisory
FAQ
What is CVE-2026-5066?
CVE-2026-5066 is a vulnerability with a CVSS score of 6.3 (MEDIUM). A potential out-of-bounds write/read exists in the TLS socket connect path of the network sockets subsystem (subsys/net/lib/sockets/sockets_tls.c). When the TLS session cache is enabled, tls_session_s...
How severe is CVE-2026-5066?
CVE-2026-5066 has been rated MEDIUM with a CVSS base score of 6.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-5066?
Check the references section above for vendor advisories and patch information. Affected products include: Zephyrproject Zephyr.