CVE-2026-63821: linux

CVSS: UnknownAwaiting analysis
AliasesUBUNTU-CVE-2026-63821DEBIAN-CVE-2026-63821
Published 19-07-2026Last modified 17-08-2026
Open JSON

Vulnerability summary

CVE-2026-63821 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.4% of scored vulnerabilities.

Overall risk
0/100
0100
Minimal · default modelHow is this calculated?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.17%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 27 · Related 26
MGASA-2026-0312OPENSUSE-SU-2026:11339-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23193-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

Risk metrics not yet published.

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

-0.01 pp

From 0.17% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.17%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu142 products
  • linuxAll versions (No fix recorded) | < 6.8.0-147.147 | < 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1067.70 | < 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.12.95-1 | < 7.1.3-1
Linux1 product
  • linux≥ a82dfd33d1237f6c0fb8a7077022189d1fc7ec98, < 2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb | ≥ a82dfd33d1237f6c0fb8a7077022189d1fc7ec98, < 53fed4061a09755de99c89fdc7fae5b794da455f | ≥ a82dfd33d1237f6c0fb8a7077022189d1fc7ec98, < 200d58c851b8f63f77a05570072dd20f79bc3681 | ≥ a82dfd33d1237f6c0fb8a7077022189d1fc7ec98, < 8206d173d18ef5a077423119f4e9a93cb3a6f4eb | ≥ a82dfd33d1237f6c0fb8a7077022189d1fc7ec98, < 6b964941bbfe6e0f18b1a5e008486dbb62df440a | 6.2

3 vendors · 144 products

References

23 links
Show all 23 references