Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
zephyrproject-rtos Zephyr — net: sockets: tls: Potential out-of-bounds write/read in socket_op_vtable::connect function
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L L N U H H H 8.8 .0032 24.9 —
AFFECTED
Product Versions Fixed
Zephyr unspecified —
TIMELINE
Mar 27 Reserved by zephyr
Jun 4 EXPLOIT PUBLISHED — CVE-2026-5066 (zephyrproject-rtos Zephyr). Public exploit reference added.
Jun 4 Published (CNA: zephyr)
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| March 27, 2026 | Reserved | Reserved by zephyr |
| June 4, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-5066 (zephyrproject-rtos Zephyr). Public exploit reference added. |
| June 4, 2026 | Published | Published (CNA: zephyr) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| zephyrproject-rtos | Zephyr | — | — | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-5066 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.