4.8 CVE-2026-10634

Enriched by CISA
 

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.
https://nvd.nist.gov/vuln/detail/CVE-2026-10634

Categories

CWE-416 : Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. If the product accesses a previously-freed pointer, then it means that a separate weakness or error already occurred previously, such as a race condition, an unexpected or poorly handled error condition, confusion over which part of the program is responsible for freeing the memory, performing the free too soon, etc. a pointer that no longer points to valid memory, often after it has been freed commonly used acronym for Use After Free Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) Use tools that are integrated duringcompilation to insert runtime error-checking mechanismsrelated to memory safety errors, such as AddressSanitizer(ASan) for C/C++ [REF-1518]. Choose a language that provides automatic memory management. When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy. TCP/IP code for an OS has a use-after-free that can leak heap memory contents Chain: an operating system kernel has insufficent resource locking (CWE-413) leading to a use after free (CWE-416). Chain: two threads in a web browser use the same resource (CWE-366), but one of those threads can destroy the resource before the other has completed (CWE-416). Chain: mobile platform race condition (CWE-362) leading to use-after-free (CWE-416), as exploited in the wild per CISA KEV. Chain: race condition (CWE-362) leads to use-after-free (CWE-416), as exploited in the wild per CISA KEV. Use-after-free triggered by closing a connection while data is still being transmitted. Improper allocation for invalid data leads to use-after-free. certificate with a large number of Subject Alternate Names not properly handled in realloc, leading to use-after-free Timers are not disabled when a related object is deleted Access to a "dead" object that is being cleaned up object is deleted even with a non-zero reference count, and later accessed use-after-free involving request containing an invalid version number unload of an object that is currently being accessed by other functionality incorrectly tracking a reference count leads to use-after-free use-after-free related to use of uninitialized memory HTML document with incorrectly-nested tags Use after free in ActiveX object by providing a malformed argument to a method use-after-free by disconnecting during data transfer, or a message containing incorrect data types disconnect during a large data transfer causes incorrect reference count, leading to use-after-free use-after-free found by fuzzing Chain: race condition (CWE-362) from improper handling of a page transition in web client while an applet is loading (CWE-368) leads to use after free (CWE-416) realloc generates new buffer and pointer, but previous pointer is still retained, leading to use after free Use-after-free in web browser, probably resultant from not initializing memory. use-after-free when one thread accessed memory that was freed by another thread assignment of malformed values to certain properties triggers use after free mail server does not properly handle a long header. chain: integer overflow leads to use-after-free freed pointer dereference Chain: A multi-threaded race condition (CWE-367) allows attackers to cause two threads to process the same RPC request, which causes a use-after-free (CWE-416) in one thread

References


 

AFFECTED (from MITRE)

Vendor Product Versions
zephyrproject zephyr
  • 2.5.0 < 4.5.0 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

cpe start end

REMEDIATION


EXPLOITS

Exploit-db.com

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POC Github

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Other Nist (github, ...)

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CAPEC

Common Attack Pattern Enumerations and Classifications

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No entry