CVE-2026-63889
scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32
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.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 27, 2026, 5:44 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Apply vendor-specific patches for Fibre Channel transport.
- Rebuild and install the updated kernel.
- Reboot the system to apply changes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63889.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63889 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63889
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63889 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63889 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': '07776b7779c9426982c1ad74aad91bd531593790', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': '29f126f09e34a425b376b3646c89aa7cc18b142c', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': '163bd704d7515c3df6c2e03bcba93d1db79edbff', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': 'ee57b89e5da9fffbe0d26647e4ff0750dacb9943', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': '35461d23744175a78b6280293892cca357c22793', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': 'bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770', 'versionType': 'git'}, {'status': 'affected', 'version': '3dcfe0de5a9752e646a61f4ce513ac059960c7c3', 'lessThan': 'a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153', 'versionType': 'git'}], 'programFiles': ['drivers/scsi/scsi_transport_fc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/scsi/scsi_transport_fc.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790 Added Reference https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff Added Reference https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c Added Reference https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793 Added Reference https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153 Added Reference https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770 Added Reference https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943