Vulnerability in Linux
CVE-2026-63889
In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32 An adjacent Fibre Channel fabric actor that can deliver an FPIN ELS frame to an lpfc or qla2xxx Linux initiator can trigger a non-return in the generic FC transport. This is not a local userspace or IP network path; the attacker must be able to inject fabric traffic, for example as a compromised switch or fabric controller, or as a same-zone N_Port on a fabric that permits source spoofing. The Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop counter against the 32-bit on-wire pname_count field, and did not bound pname_count by the descriptor body already validated by the TLV walker. A pname_count of 256 therefore wraps the counter and keeps the loop condition true indefinitely. Factor the shared pname_list[] walk into one helper, widen the counter to u32, and clamp pname_count against the entries that fit in the descriptor body before iterating.
EPSS: 0.004 (28.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
Affected products
- Linux — versions 3dcfe0de5a9752e646a61f4ce513ac059960c7c3, 5.11, 0
References
Frequently asked questions
- What is CVE-2026-63889?
- CVE-2026-63889 is a high-severity vulnerability in Linux. CVSS score: 8.1/10. Published 2026-07-19.
- How severe is CVE-2026-63889?
- High severity. CVSS v3 base score is 8.1 out of 10.