CVE-2026-64369
s390: Revert support for DCACHE_WORD_ACCESS
Description
In the Linux kernel, the following vulnerability has been resolved: s390: Revert support for DCACHE_WORD_ACCESS load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory")
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Revert the load_unaligned_zeropad function.
- Apply a proper fix for secure storage access exceptions.
- Update the Linux kernel to the latest secure version.
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-2026-64369.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64369 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-2026-64369
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-2026-64369 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64369 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': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c9e0f1517631ac08987f8385817119bccf2f1f12', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'be79d285bea70d0edd5015bd487311bfa8cbebc9', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c94806905e02cc8e17a69c822d93c41743b7ffc5', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': '37540b8c287fc817bdbd0c62bb75ad6eab0e5d03', 'versionType': 'git'}], 'programFiles': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.97', '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': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c9e0f1517631ac08987f8385817119bccf2f1f12', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'be79d285bea70d0edd5015bd487311bfa8cbebc9', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c94806905e02cc8e17a69c822d93c41743b7ffc5', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': '37540b8c287fc817bdbd0c62bb75ad6eab0e5d03', 'versionType': 'git'}], 'programFiles': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.97', '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': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'affected'}] -
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': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c9e0f1517631ac08987f8385817119bccf2f1f12', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'be79d285bea70d0edd5015bd487311bfa8cbebc9', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': 'c94806905e02cc8e17a69c822d93c41743b7ffc5', 'versionType': 'git'}, {'status': 'affected', 'version': '802ba53eefc592a6a82231f74e19bafe3256f172', 'lessThan': '37540b8c287fc817bdbd0c62bb75ad6eab0e5d03', 'versionType': 'git'}], 'programFiles': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.97', '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': ['arch/s390/Kconfig', 'arch/s390/include/asm/asm-extable.h', 'arch/s390/include/asm/word-at-a-time.h', 'arch/s390/mm/extable.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: s390: Revert support for DCACHE_WORD_ACCESS load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory") Added Reference https://git.kernel.org/stable/c/37540b8c287fc817bdbd0c62bb75ad6eab0e5d03 Added Reference https://git.kernel.org/stable/c/be79d285bea70d0edd5015bd487311bfa8cbebc9 Added Reference https://git.kernel.org/stable/c/c94806905e02cc8e17a69c822d93c41743b7ffc5 Added Reference https://git.kernel.org/stable/c/c9e0f1517631ac08987f8385817119bccf2f1f12