What’s Vulnerable › Vulnerabilities

CVE-2026-5066: net: sockets: tls: Potential out-of-bounds write/read in socket_op_vtable::connect function

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-06-04 · updated 2026-10-15
• Weakness: CWE-787

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

• zephyrproject zephyr: through 4.3.0

References

• https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-24f3
• https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-24f3

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