Integer overflow in Linux kernel - CVE-2026-63889
Published: July 20, 2026
Vulnerability identifier: #VU138756
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-63889
CWE-ID: CWE-190
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an infinite loop caused by an integer truncation error in the FPIN pname walker in scsi_transport_fc when processing a crafted FPIN ELS frame. A remote attacker can send a crafted Fibre Channel fabric frame to cause a denial of service.
Exploitation requires the ability to inject Fibre Channel fabric traffic to an lpfc or qla2xxx Linux initiator, such as from a compromised switch or fabric controller, or from a same-zone N_Port on a fabric that permits source spoofing.
How to mitigate CVE-2026-63889
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790
- https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff
- https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c
- https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793
- https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153
- https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770
- https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943