CVE WatchJul 14, 2026

CVE-2026-31665

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: fix use-after-free in timeout object destroy nft_ct

CVSS

7.8

High

EPSS

0.1%

KEV

—

Exploit Today

0-100

Published: Apr 24, 2026 · Last modified: Jul 14, 2026 · CWE-416

EPSS · 30d

0.1%EPSS · 30 days0.1%

2026-08-032026-08-31

Technical description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: fix use-after-free in timeout object destroy nft_ct_timeout_obj_destroy() frees the timeout object with kfree() immediately after nf_ct_untimeout(), without waiting for an RCU grace period. Concurrent packet processing on other CPUs may still hold RCU-protected references to the timeout object obtained via rcu_dereference() in nf_ct_timeout_data(). Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer freeing until after an RCU grace period, matching the approach already used in nfnetlink_cttimeout.c. KASAN report: BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0 Read of size 4 at addr ffff8881035fe19c by task exploit/80 Call Trace: nf_conntrack_tcp_packet+0x1381/0x29d0 nf_conntrack_in+0x612/0x8b0 nf_hook_slow+0x70/0x100 __ip_local_out+0x1b2/0x210 tcp_sendmsg_locked+0x722/0x1580 __sys_sendto+0x2d8/0x320 Allocated by task 75: nft_ct_timeout_obj_init+0xf6/0x290 nft_obj_init+0x107/0x1b0 nf_tables_newobj+0x680/0x9c0 nfnetlink_rcv_batch+0xc29/0xe00 Freed by task 26: nft_obj_destroy+0x3f/0xa0 nf_tables_trans_destroy_work+0x51c/0x5c0 process_one_work+0x2c4/0x5a0

Official references

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CVE-2026-143666.4 MED

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———The Silicon Labs SiWx917 WiFi driver's transmit callback siwx91x_send() in drivers/wifi/siwx91x/siwx91x_wifi.c frees a network packet it does not own. In the Zephyr TX path the net_pkt is owned by the L2/networking stack; the driver only borrows it to copy the frame bytes into a local net_buf. Before the fix, after transmitting, siwx91x_send() additionally called net_pkt_unref(pkt) on the caller-owned packet, dropping its last reference and returning it to the shared packet pool prematurely. This code path is compiled in by default (CONFIG_WIFI_SILABS_SIWX91X_NET_STACK_NATIVE). The caller, ethernet_send() in subsys/net/l2/ethernet/ethernet.c, keeps using the packet after the driver returns: it reads net_pkt_get_len(pkt), updates TX statistics, and then performs its own net_pkt_unref(pkt). Because the driver already released the packet, these are use-after-free reads followed by a second unref (a double free). When concurrent network activity recycles the freed slab slot between the two unrefs, the trailing unref decrements a different, live packet's reference count and frees it, corrupting the net_pkt pool shared by both the receive and transmit paths. The defect is exercised by ordinary transmission over the native-stack SiWx917 WiFi interface, and an adjacent attacker on the same WiFi network can induce transmissions (for example ARP or ICMP echo replies, or TCP handshakes) to drive the path. The primary observable impact is loss of availability (transmit hangs and crashes from pool corruption), with race-dependent memory corruption of the kernel networking buffer pool. The fix removes the erroneous net_pkt_unref(pkt) from siwx91x_send(); the driver's receive-path unref, which correctly frees a packet the driver itself allocated, is unaffected.19h CVE-2026-826312.2 LOW

28.8%

——9A security flaw has been discovered in valkey-io valkey 9.1.0. The affected element is the function handleClientsBlockedOnKey of the file src/blocked.c of the component Blocked-on-keys Subsystem. The manipulation results in use after free. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The patch is identified as b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b. Applying a patch is advised to resolve this issue.1d CVE-2026-826235.3 MED

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——10A vulnerability was detected in open62541 up to 1.5.5. Affected by this vulnerability is the function UA_DataValue_backend_copyRange of the file plugins/historydata/ua_history_data_backend_memory.c of the component History Backend. The manipulation results in use after free. The attack can be launched remotely. The exploit is now public and may be used. The project closed the issue report, stating that this is not the official way to report a security vulnerability.19h CVE-2026-826194.3 MED

22.4%

——7A vulnerability was identified in Systerel S2OPC up to 1.7.3. The impacted element is the function monitored_item_event_filter_treatment_bs__init_event_filter_ctx_and_result of the file src/ClientServer/services/bgenc/subscription_mgr.c. Such manipulation of the argument EventFilter leads to use after free. The attack may be performed from remote. The exploit is publicly available and might be used. The name of the patch is a4cee16a851b971be447a6ed531173702c722b99. It is best practice to apply a patch to resolve this issue.20h CVE-2026-667984.3 MED

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——13Use after free in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.14h CVE-2026-420079.1 CRI

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——6An attacker that has valid credentials can use a Sieve script with the editheader extension to trigger a use-after-free in the mail editing code, and to write memory contents beyond the intended buffer into the delivered mail. This causes memory leak and opportunity to do memory corruption during mail delivery, which can crash the delivery process and may allow execution of arbitrary code in the context of that process. Disable the Sieve editheader extension. Update to non-vulnerable version. No publicly available exploits are known.4d