CVE-2026-10634 (GCVE-0-2026-10634)

Vulnerability from cvelistv5 – Published: 2026-06-15 14:16 – Updated: 2026-10-15 22:09
VLAI
Title
Use-after-free in Zephyr native TCP `net_tcp_foreach()` due to dropping `tcp_lock` during the callback
Summary
Zephyr's native TCP stack iterates the global connection list in net_tcp_foreach() (subsys/net/ip/tcp.c) using the SYS_SLIST_FOR_EACH_CONTAINER_SAFE macro, which caches a pointer to the next list node. Prior to this fix the function released tcp_lock while invoking the per-connection callback and re-acquired it afterwards. During that window a concurrent tcp_conn_release(), running on the dedicated TCP work-queue thread when a connection's reference count drops to zero (e.g. a remote peer closing or resetting the connection), can remove and k_mem_slab_free() the cached next connection. When the iterator advances it dereferences the freed (and possibly reallocated) slab memory — a use-after-free that can crash the system (denial of service) and, if the slot has been reused, cause the callback to operate on an attacker-influenced object (potential information disclosure or further fault). net_tcp_foreach() is reached in production via the net conn network shell command and via net_tcp_close_all_for_iface() on interface-down; the freeing side is driven by ordinary TCP traffic. The fix moves the connection/context teardown in tcp_conn_release() inside the tcp_lock critical section and keeps tcp_lock held across the callback in net_tcp_foreach(). The defect was introduced with the modern (TCP2) stack in 2020 and affects releases up to and including v4.4.0.
Severity
4.8 (Medium)
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-15 16:06 UTC
CWE
Assigner
zephyr CNA under the mitre root
CNA scorecard B 77/100 over 200 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
zephyrproject zephyr Affected: 3.6.0 , < 4.3.1 (semver)
Affected: 4.4.0 , < 4.4.1 (semver)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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