TI-2026-09140 Aliases CVE-2026-10638 GHSA-wqjx-hrch-347f

Use-after-free in Zephyr ICMPv6 RX path when updating statistics after sending an echo reply or error

LOW 33CWE-416Published 2026-06-16 · Updated 2026-11-04

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.

Summary

subsys/net/ip/icmpv6.c reads the network interface from a net_pkt after that packet has been handed to net_try_send_data(). In icmpv6_handle_echo_request() and net_icmpv6_send_error(), the post-send statistics update calls net_pkt_iface(reply)/net_pkt_iface(pkt) on the just-sent packet. The send path (net_try_send_data -> net_if_tx) unreferences and may free the packet back to its memory slab before returning — synchronously in the RX thread when no TX queue is configured (CONFIG_NET_TC_TX_COUNT == 0), and asynchronously the driver/L2 may already have freed it otherwise. net_pkt_iface() therefore dereferences a freed (and possibly reused) net_pkt; with CONFIG_NET_STATISTICS_PER_INTERFACE the stale iface pointer is further dereferenced and written through (iface->stats.icmp.sent++), turning the use-after-free read into a write through an attacker-influenceable pointer. The core stack already documents this hazard in net_core.c ("do not use pkt after that call") and caches iface before sending; the ICMPv6 callers did not. An unauthenticated remote attacker triggers the flaw simply by sending an ICMPv6 Echo Request (ping) or an IPv6 packet that elicits an ICMPv6 error (unknown next header, fragment reassembly timeout, destination unreachable), leading to denial of service via crash and potential memory corruption. Affected: Zephyr networking with CONFIG_NET_NATIVE_IPV6, roughly v4.2.0 through v4.4.0. The fix caches the interface pointer before sending and uses it for all statistics updates; the sibling commit 86e21665d46 fixes the identical bug in ICMPv4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00352 29th percentileScored 2026-11-07

Fix Fixed zephyr (zephyrproject): 4.3.1, 4.4.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
zephyrproject	zephyr	3.7.0 to before 4.3.1; 4.4.0 to before 4.4.1	4.3.1, 4.4.1	Patch available	CNA

zephyr Vendorzephyrproject Affected 3.7.0 to before 4.3.1; 4.4.0 to before 4.4.1 Fixed in 4.3.1, 4.4.1 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:zephyrproject:zephyr::::::::	4.2.0 to before 4.5.0	Vulnerable	zephyrproject

cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:* Versions 4.2.0 to before 4.5.0 Vulnerable ·zephyrproject

Remediation

Fix · CNA zephyr (zephyrproject) Fixed in 4.3.1, 4.4.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-06-16
zephyrproject zephyr 4.3.1, 4.4.1
5 records Highest priority Priority LOW 5 LOW
Other records, highest priority first
- TI-2026-09142 Use-after-free reading `net_pkt` `iface` after send in IPv6 Neighbor Discovery (`ipv6_nbr.c`)Priority LOW 31
- TI-2026-09139 Use-after-free of `net_pkt` in IPv6 MLD send path triggerable by a link-local MLD QueryPriority LOW 31
- TI-2026-09141 Use-after-free reading `net_pkt_iface()` of a sent ICMPv4 echo-reply packet in `icmpv4_handle_echo_request()`Priority LOW 22
Show all 5 records →

Timeline

2026-10-02 Threatist record created from CVE-2026-10638
2026-10-03 Alias added: GHSA-wqjx-hrch-347f
2026-10-16 Fix available: [email protected], [email protected] · CNA

References

Patch 1

Fix commit

Other 1

GHSA-m92g-94xv-wvw2

TI-2026-04422 Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key CVSS 3.1CRITICAL 9.8
TI-2026-01361 dns: memory‑safety issue in the DNS name parser CVSS 3.1CRITICAL 9.8
TI-2026-09174 Unterminated URI buffer causes out-of-bounds read in LwM2M firmware pull (Package URI) CVSS 3.1CRITICAL 9.1
TI-2026-09168 Stack buffer overflow in `net_ipaddr_parse()` IPv4 address-with-port parsing in `subsys/net/ip/utils.c` CVSS 3.1CRITICAL 9.8
TI-2024-09625 net: lib: http_server: Buffer Under-read CVSS 3.1HIGH 8.6
TI-2021-02863 Usb bluetooth device ACL read cb buffer overflow CVSS 3.1CRITICAL 9.6

See all 196 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences