Kernel memory leaks via ignored USB failures
Published Jul 19, 2026 · Updated Jul 19, 2026
Memory leaks in the rtw88 USB Wi-Fi driver in affected Linux Kernel releases allow attackers to consume memory after USB write failures. rtw_usb_write_data() and rtw_usb_tx_agg_skb() ignore failed URB submission, so callbacks never free socket buffers, aggregated buffers, or the transaction control block. Reachability requires rtw88 USB transmission plus a submission failure, such as device disconnect or memory pressure; no resulting crash is reported.
Summary
What happened
Memory leaks in the rtw88 USB Wi-Fi driver in affected Linux Kernel releases allow attackers to consume memory after USB write failures. rtw_usb_write_data() and rtw_usb_tx_agg_skb() ignore failed URB submission, so callbacks never free socket buffers, aggregated buffers, or the transaction control block. Reachability requires rtw88 USB transmission plus a submission failure, such as device disconnect or memory pressure; no resulting crash is reported.
The record
- CVE
- CVE-2026-63821
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.2
- Affected versionversion=a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 <200d58c851b8f63f77a05570072dd20f79bc3681
- Affected versionversion=a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 <2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb
- Affected versionversion=a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 <53fed4061a09755de99c89fdc7fae5b794da455f
- Affected versionversion=a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 <6b964941bbfe6e0f18b1a5e008486dbb62df440a
- Affected versionversion=a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 <8206d173d18ef5a077423119f4e9a93cb3a6f4eb
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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