CVE-2026-74556
Received
Received - Intake
BaseFortify
Vulnerability report for CVE-2026-74556, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-15
Last updated on: 2026-08-15
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer
iscsi_tcp_hdr_dissect() receives the data segment of several PDU types
into the fixed-size conn->data buffer, which is allocated for
ISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP,
REJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU
whose DataSegmentLength exceeds that buffer.
The SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its
data segment (sense/response data) into conn->data via
iscsi_tcp_data_recv_prep(), but it does so without the same check. The
only upstream bound on in.datalen is conn->max_recv_dlength, the
initiator's advertised MaxRecvDataSegmentLength, which is commonly
negotiated well above 8192 (open-iscsi defaults to 262144). A target
that returns a SCSI Response with a DataSegmentLength between 8193 and
max_recv_dlength therefore overflows the 8192-byte conn->data buffer.
Once the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly
like those responses: bound the data segment, receive it into conn->data
when present, and otherwise complete the PDU with no data. Fold the
opcode into that case group rather than duplicating the check.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| iscsi | libiscsi_tcp | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
