CVE-2026-64048
HighIn the Linux kernel, the following vulnerability has been resolved: net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot On the SMC-D client, slot 0 of ini->ism_dev[]/ini->ism_chid[] is reserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt() populates V2 entries starting at index 1, so when no V1 device is selected slot 0 is left in its kzalloc()'ed state with ism_dev[0] == NULL and ism_chid[0] == 0. smc_v2_determine_accepted_chid() then matches the peer's CHID against the array starting from index 0 using the CHID alone. A malicious peer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches the empty slot, ini->ism_selected becomes 0, and the subsequent ism_dev[0]->lgr_lock dereference in smc_conn_create() faults at offsetof(struct smcd_dev, lgr_lock) == 0x68: BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0 Write of size 4 at addr 0000000000000068 by task exploit/144 Call Trace: _raw_spin_lock_bh smc_conn_create (net/smc/smc_core.c:1997) __smc_connect (net/smc/af_smc.c:1447) smc_connect (net/smc/af_smc.c:1720) __sys_connect __x64_sys_connect do_syscall_64 Require ism_dev[i] to be non-NULL before accepting a CHID match.
CVSS 3.1 score
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-476CVE-2026-64048 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.10
and later are affected. Fixed in
5.10.266,
5.15.217,
6.1.175,
6.6.142,
6.12.92,
6.18.34,
7.0.11,
7.1
and their respective stable series.
References
8 total-
Patch
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Frequently asked questions
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What is CVE-2026-64048?
CVE-2026-64048 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.10 onward and has been patched in 5.10.266, 5.15.217, 6.1.175 and others. CVE-2026-64048 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-64048?
CVE-2026-64048 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-64048?
Yes. CVE-2026-64048 has been patched. Fixed versions include 5.10.266, 5.15.217, 6.1.175 and others. If you are running Linux kernel 5.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64048 actively exploited?
No. CVE-2026-64048 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.