CVE-2026-63889

HIGH
MEDIUM Priority: 0.03 BB Relevance: 61/100
Published: 2026-07-19 Modified: 2026-10-29 First seen: 2026-10-29 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Adjacent
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: None
A: High

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 iterating.

Weakness Classification (2)

Affected Software (6)

VendorProductVersion
linux linux_kernel 5.11 – 5.15.210
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1

Bug Bounty Relevance

61 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.1 / 10.0 v3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS — Exploitation Probability

0.36%
Raw Score 0.003590
Percentile 29.6%
Date 2026-10-29

Intelligence Sources

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