CVE WatchAug 26, 2026

CVE-2026-53185

In the Linux kernel, the following vulnerability has been resolved: zram: fix use-after-free in zram_bvec_write_partial() zram_read_page()

CVSS

7.8

High

EPSS

0.1%

KEV

—

Exploit Today

0-100

Published: Jun 25, 2026 · Last modified: Aug 26, 2026 · CWE-416 · CWE-364

EPSS · 30d

0.1%EPSS · 30 days0.1%

2026-08-022026-08-31

Technical description

In the Linux kernel, the following vulnerability has been resolved: zram: fix use-after-free in zram_bvec_write_partial() zram_read_page() picks the sync or async backing device read path based on whether the parent bio is NULL. zram_bvec_write_partial() passes its parent bio down, so for ZRAM_WB slots the read is dispatched asynchronously and zram_read_page() returns 0 while the bio is still in flight. The caller then runs memcpy_from_bvec(), zram_write_page() and __free_page() on the buffer, leaving the async read to write into a freed page. zram_bvec_read_partial() was switched to NULL in commit 4e3c87b9421d ("zram: fix synchronous reads") for the same reason; the write_partial counterpart was missed.

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.2h CVE-2026-826312.2 LOW

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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.2h CVE-2026-826194.3 MED

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——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.3h 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.3d 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.3d