In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: usb: fix memory leaks on USB write failures When rtw_usb_write_port() fails to submit a USB Request Block (URB) (e.g., due to device disconnect or ENOMEM), the completion callback is never executed. Currently, the driver ignores the return value of rtw_usb_write_port() in rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these functions rely on the completion callback to free the socket buffers (skbs) and the transaction control block (txcb), a submission failure results in: 1. A memory leak of the allocated skb in rtw_usb_write_data(). 2. A memory leak of the txcb structure and all aggregated skbs in rtw_usb_tx_agg_skb(). Fix this by checking the return value of rtw_usb_write_port(). If it fails, explicitly free the skb in rtw_usb_write_data(), and properly purge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb(). The issue was discovered in practice during device disconnect/reconnect scenarios and memory pressure conditions. Tested by verifying normal TX operation continues after the fix without regressions.

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - wifi: rtw88: usb: fix memory leaks on USB write failures When rtw_usb_write_port() fails to submit a USB     Request Block (URB) (e.g., due to device disconnect or ENOMEM), the completion callback is never executed.
    Currently, the driver ignores the return value of rtw_usb_write_port() in rtw_usb_write_data() and     rtw_usb_tx_agg_skb(). Because these functions rely on the completion callback to free the socket buffers     (skbs) and the transaction control block (txcb), a submission failure results in: 1. A memory leak of the     allocated skb in rtw_usb_write_data(). 2. A memory leak of the txcb structure and all aggregated skbs in     rtw_usb_tx_agg_skb(). Fix this by checking the return value of rtw_usb_write_port(). If it fails,     explicitly free the skb in rtw_usb_write_data(), and properly purge the tx_ack_queue and free the txcb in     rtw_usb_tx_agg_skb(). The issue was discovered in practice during device disconnect/reconnect scenarios     and memory pressure conditions. Tested by verifying normal TX operation continues after the fix without     regressions. (CVE-2026-63821)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
343049	Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2026-500248)	Nessus	Oracle Linux Local Security Checks	Local	high
341024	SUSE SLED15: cluster-md-kmp-default / dlm-kmp-default / gfs2-kmp-default / etc (SUSE-SU-2026:3790-1)	Nessus	SuSE Local Security Checks	Local	high
335080	openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21555-1)	Nessus	SuSE Local Security Checks	Local	high
333954	Photon OS 5.0: Linux PHSA-2026-5.0-92-0916	Nessus	PhotonOS Local Security Checks	Local	high
328198	Linux Distros Unpatched Vulnerability : CVE-2026-63821	Nessus	Misc.	Local	medium
326038	Photon OS 5.0: Linux PHSA-2026-5.0-0916	Nessus	PhotonOS Local Security Checks	Local	high

Detections

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CVE-2026-63821

medium

Tenable Plugins

high

high

high

high

medium

high