CVE-2026-64320
nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page
Description
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page nvmet_execute_disc_get_log_page() validates only the dword alignment of the host-supplied Log Page Offset (lpo). The 64-bit offset is then added to a small kzalloc'd buffer that holds the discovery log page and the result is passed straight to nvmet_copy_to_sgl(), which memcpy()s data_len bytes out to the host with no source-side bound check: u64 offset = nvmet_get_log_page_offset(req->cmd); /* 64-bit host */ size_t data_len = nvmet_get_log_page_len(req->cmd); /* 32-bit host */ ... if (offset & 0x3) { ... } /* only check */ ... alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req); buffer = kzalloc(alloc_len, GFP_KERNEL); ... status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len); The Discovery controller is unauthenticated -- nvmet_host_allowed() returns true unconditionally for the discovery subsystem -- so the call is reachable pre-authentication by any TCP/RDMA/FC peer that can reach the nvmet target. With a discovery log page of ~1 KiB, an attacker requesting up to 4 KiB starting at offset == alloc_len reads the next slab page out and gets its content returned over the fabric (an empirical run on a default nvmet-tcp loopback target leaked 81 canonical kernel pointers in one Get Log Page response). Pointing the offset at unmapped kernel memory faults the in-kernel memcpy and crashes (or panics, on panic_on_oops=1) the target host instead. The attacker-controlled source-side offset pattern "nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)" is unique to nvmet_execute_disc_get_log_page in the entire nvmet codebase: every other Get Log Page handler in admin-cmd.c either ignores lpo (and silently starts every response at offset 0) or tracks a local destination offset with a fixed source pointer. Validate the host-supplied offset against the log page size, cap the copy length to what is actually available, and zero-fill any remainder of the host transfer buffer. The zero-fill matches the existing short-response pattern in nvmet_execute_get_log_changed_ns() (admin-cmd.c) and prevents leaking transport SGL contents when the host asks for more bytes than the log page contains.
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Validate host-supplied offset against log page size.
- Cap copy length to available data.
- Zero-fill remainder of host transfer buffer.
- Apply vendor-provided patches.
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-2026-64320.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64320 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-2026-64320
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-2026-64320 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64320 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
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '33b974eb626154ae9348f2bac7de84cb2a3d9dd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '56c021a0869260d04c4b65d1471936aaf9177114', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': 'a29b316b9bbfd269f323ab4ba9906a894025680f', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '53cd102a7a56079b11b897835bd9b94c14e6322c', 'versionType': 'git'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.8'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.8', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '33b974eb626154ae9348f2bac7de84cb2a3d9dd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '56c021a0869260d04c4b65d1471936aaf9177114', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': 'a29b316b9bbfd269f323ab4ba9906a894025680f', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '53cd102a7a56079b11b897835bd9b94c14e6322c', 'versionType': 'git'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.8'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.8', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 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': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '33b974eb626154ae9348f2bac7de84cb2a3d9dd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '56c021a0869260d04c4b65d1471936aaf9177114', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': 'a29b316b9bbfd269f323ab4ba9906a894025680f', 'versionType': 'git'}, {'status': 'affected', 'version': 'a07b4970f464f13640e28e16dad6cfa33647cc99', 'lessThan': '53cd102a7a56079b11b897835bd9b94c14e6322c', 'versionType': 'git'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.8'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.8', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/nvme/target/discovery.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page nvmet_execute_disc_get_log_page() validates only the dword alignment of the host-supplied Log Page Offset (lpo). The 64-bit offset is then added to a small kzalloc'd buffer that holds the discovery log page and the result is passed straight to nvmet_copy_to_sgl(), which memcpy()s data_len bytes out to the host with no source-side bound check: u64 offset = nvmet_get_log_page_offset(req->cmd); /* 64-bit host */ size_t data_len = nvmet_get_log_page_len(req->cmd); /* 32-bit host */ ... if (offset & 0x3) { ... } /* only check */ ... alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req); buffer = kzalloc(alloc_len, GFP_KERNEL); ... status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len); The Discovery controller is unauthenticated -- nvmet_host_allowed() returns true unconditionally for the discovery subsystem -- so the call is reachable pre-authentication by any TCP/RDMA/FC peer that can reach the nvmet target. With a discovery log page of ~1 KiB, an attacker requesting up to 4 KiB starting at offset == alloc_len reads the next slab page out and gets its content returned over the fabric (an empirical run on a default nvmet-tcp loopback target leaked 81 canonical kernel pointers in one Get Log Page response). Pointing the offset at unmapped kernel memory faults the in-kernel memcpy and crashes (or panics, on panic_on_oops=1) the target host instead. The attacker-controlled source-side offset pattern "nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)" is unique to nvmet_execute_disc_get_log_page in the entire nvmet codebase: every other Get Log Page handler in admin-cmd.c either ignores lpo (and silently starts every response at offset 0) or tracks a local destination offset with a fixed source pointer. Validate the host-supplied offset against the log page size, cap the copy length to what is actually available, and zero-fill any remainder of the host transfer buffer. The zero-fill matches the existing short-response pattern in nvmet_execute_get_log_changed_ns() (admin-cmd.c) and prevents leaking transport SGL contents when the host asks for more bytes than the log page contains. Added Reference https://git.kernel.org/stable/c/33b974eb626154ae9348f2bac7de84cb2a3d9dd4 Added Reference https://git.kernel.org/stable/c/53cd102a7a56079b11b897835bd9b94c14e6322c Added Reference https://git.kernel.org/stable/c/56c021a0869260d04c4b65d1471936aaf9177114 Added Reference https://git.kernel.org/stable/c/a29b316b9bbfd269f323ab4ba9906a894025680f