CVE-2026-63795: 9p: avoid putting oldfid in p9_client_walk() error path
9p: avoid putting oldfid in p9clientwalk() error path
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.150.1-1 - Compensating control
Apply the kernel vulnerability resolution for 9p to ensure p9_client_walk() only puts/clunks oldfid in the clunk_fid error path when it does not violate ownership/refcount expectations—i.e., only put fid/clunk oldfid in that error path when the walk subsequently fails after the request has been sent and when oldfid can be clunked because it is the last reference.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-63795?
The severity of CVE-2026-63795 is critical with a CVSS score of 10.
What does CVE-2026-63795 affect in the Linux kernel?
CVE-2026-63795 affects the p9_client_walk() function in the Linux kernel, specifically in its error handling.
How do I fix CVE-2026-63795?
To fix CVE-2026-63795, update the Linux kernel to the latest version that addresses this vulnerability.
What type of vulnerability is CVE-2026-63795 classified as?
CVE-2026-63795 is classified as a use after free vulnerability.
When was CVE-2026-63795 published?
CVE-2026-63795 was published on July 19, 2026.