CVE-2026-43274 | mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()

In the Linux kernel, the following vulnerability has been resolved: mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq() The cluster_cfg array is dynamically allocated to hold per-CPU configuration structures, with its size based on the number of online CPUs. Previously, this array was indexed using hartid, which may be non-contiguous or exceed the bounds of the array, leading to out-of-bounds access. Switch to using cpuid as the index, as it is guaranteed to be within the valid range provided by for_each_online_cpu().

Published: 2026-05-06 Last update: 2026-05-08 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43274 is rated Low Risk (35/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-43274

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-07 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43274

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.4 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Weakness enumeration for CVE-2026-43274

GitHub Security Advisory for CVE-2026-43274

GHSA-w4mh-vmr5-87jc · Severity: high — In the Linux kernel, the following vulnerability has been resolved: mailbox: mchp-ipc-sbi: fix...

OS Trackers for CVE-2026-43274

vendor priority summary link
debian unimportant CVE-2026-43274 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-43274
redhat — — https://access.redhat.com/security/cve/CVE-2026-43274
suse medium CVE-2026-43274 severity moderate: SUSE including 21 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 198 product×package rows across 39 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (39 product lines)): Known Not Affected 198. https://www.suse.com/security/cve/CVE-2026-43274/
ubuntu medium CVE-2026-43274 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1048, ignored 173, needed 130, released 83, not-affected 10, needs-triage 5. https://ubuntu.com/security/CVE-2026-43274

Affected software / configurations for CVE-2026-43274

Vendor Product Version Raw CPE
linux linux_kernel >= 6.14, < 6.18.16 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19, < 6.19.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2026-43274

cvelogic Threat Intelligence