High severity · published Jun 4, 2026
CVE-2026-5066
net: sockets: tls: Potential out-of-bounds write/read in socket_op_vtable::connect function
8.8
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZE
Zephyr · zephyrproject-rtos
before 3.7.2; 4.0.0 before 4.2.2; 4.3.0 before 4.3.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5066
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5066
Exploit
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-24f3
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