CVE-2026-63889EPSS p27.3%
CVE-2026-63889CVE-2026-63889
Description
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 ite
Scoring
| CVSS | 8.1 () |
| Vector | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| EPSS | 0.36% probability of exploitation · percentile 27.3% · 2026-10-05T12:00:23Z |
| Last modified | 2026-07-27 |