---
cve: "CVE-2026-63889"
severity: "HIGH"
cvss: 8.1
epss: "36%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 16:17:06"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-17T09:23:20+02:00"
---

# CVE-2026-63889

> 8.1 HIGH

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Benachbart | warn |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 5.15.210
- Kernel ≥ 6.1.176
- Kernel ≥ 6.6.143
- Kernel ≥ 6.12.93
- Kernel ≥ 6.18.35
- Kernel ≥ 7.0.12

## Referenzen

- <https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790>
- <https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c>
- <https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff>
- <https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943>
- <https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793>
- <https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770>
- <https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63889) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_