CVE-2026-64004
net/iucv: fix locking in .getsockopt
Description
In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 30, 2026, 2:51 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 the provided patch for net/iucv.
- Review socket locking mechanisms.
- Test the fix thoroughly.
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-2026-64004.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64004 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-2026-64004
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-2026-64004 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64004 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '884eb247b74d86db97e3a37f0d6fc8e1e83590dd', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '45bb8de8c95d8899f4b8f61bd9bceb8132af73cb', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '1fc30bd4e55e2dd622d2d366cecd732c1841bbee', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': 'cd691beafea0dd779e69e81ccc26b0ab50efcb5e', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '6e792b8dd3002bbc4136745928a9605df1a72b8a', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '9817369243380e287ebe5525411557eaa3aa2a79', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '69554adc7a6fa04ede3ad7512321d83748e3c920', 'versionType': 'git'}, {'status': 'affected', 'version': '51363b8751a673a00ad48eea895266396d53fa52', 'lessThan': '3589d20a666caf30ad100c960a2de7de390fce88', 'versionType': 'git'}], 'programFiles': ['net/iucv/af_iucv.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'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': ['net/iucv/af_iucv.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops. Added Reference https://git.kernel.org/stable/c/1fc30bd4e55e2dd622d2d366cecd732c1841bbee Added Reference https://git.kernel.org/stable/c/3589d20a666caf30ad100c960a2de7de390fce88 Added Reference https://git.kernel.org/stable/c/45bb8de8c95d8899f4b8f61bd9bceb8132af73cb Added Reference https://git.kernel.org/stable/c/69554adc7a6fa04ede3ad7512321d83748e3c920 Added Reference https://git.kernel.org/stable/c/6e792b8dd3002bbc4136745928a9605df1a72b8a Added Reference https://git.kernel.org/stable/c/884eb247b74d86db97e3a37f0d6fc8e1e83590dd Added Reference https://git.kernel.org/stable/c/9817369243380e287ebe5525411557eaa3aa2a79 Added Reference https://git.kernel.org/stable/c/cd691beafea0dd779e69e81ccc26b0ab50efcb5e