Vulnerability · Published Jun 4, 2026 · Assigned by zephyr
CVE-2026-5066net: sockets: tls: Potential out-of-bounds write/read in socket_op_vtable::connect function
Medium 6.3
In plain English
A medium-severity out-of-bounds write in Zephyr from zephyrproject-rtos. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| zephyrproject-rtos | Zephyr | * – before 3.7.24.0.0 – before 4.2.24.3.0 – before 4.3.1 |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L