CVE-2026-74556
scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer
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.
INFO
Published Date :
Aug. 15, 2026, 1:18 p.m.
Last Modified :
Aug. 15, 2026, 1:18 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74556
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to a patched version.
- Verify the kernel version after applying the update.
- Reboot the system if necessary.
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-2026-74556.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74556 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-2026-74556
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-2026-74556 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74556 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 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': 'a081c13e39b5c17052a7b46fafa61019c4c110ff', 'lessThan': 'c97b5265cc47775f77fd2a23d6bde0426997b233', 'versionType': 'git'}, {'status': 'affected', 'version': 'a081c13e39b5c17052a7b46fafa61019c4c110ff', 'lessThan': '084af0253673425ce2ae62e3c7f74f0dd023711b', 'versionType': 'git'}, {'status': 'affected', 'version': 'a081c13e39b5c17052a7b46fafa61019c4c110ff', 'lessThan': '72815741715bd41556dac5eeb068bf0f8af06ee7', 'versionType': 'git'}, {'status': 'affected', 'version': 'a081c13e39b5c17052a7b46fafa61019c4c110ff', 'lessThan': 'b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676', 'versionType': 'git'}, {'status': 'affected', 'version': 'a081c13e39b5c17052a7b46fafa61019c4c110ff', 'lessThan': 'c1dea15f819cded9b3faf58f8bec72323568b6e6', 'versionType': 'git'}], 'programFiles': ['drivers/scsi/libiscsi_tcp.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2.6.29'}, {'status': 'unaffected', 'version': '0', 'lessThan': '2.6.29', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.151', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.103', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/scsi/libiscsi_tcp.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/084af0253673425ce2ae62e3c7f74f0dd023711b Added Reference https://git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7 Added Reference https://git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676 Added Reference https://git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6 Added Reference https://git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233