CVE-2026-43097

CVE-2026-43097 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: PCI: hv: Fix double ida_free in hv_pci_probe error path If hv_pci_probe() fails after storing the domain number in hbus->bridge->domain_nr, there is a call to free this domain_nr via pci_bus_release_emul_domain_nr(), however, during cleanup, the bridge release callback pci_release_host_bridge_dev() also frees the domain_nr causing ida_free to be called on same ID twice and triggering following warning: ida_free called for id=28971 which is not allocated. WARNING: lib/idr.c:594 at ida_free+0xdf/0x160, CPU#0: kworker/0:2/198 Call Trace: pci_bus_release_emul_domain_nr+0x17/0x20 pci_release_host_bridge_dev+0x4b/0x60 device_release+0x3b/0xa0 kobject_put+0x8e/0x220 devm_pci_alloc_host_bridge_release+0xe/0x20 devres_release_all+0x9a/0xd0 device_unbind_cleanup+0x12/0xa0 really_probe+0x1c5/0x3f0 vmbus_add_channel_work+0x135/0x1a0 Fix this by letting pci core handle the free domain_nr and remove the explicit free called in pci-hyperv driver.

Frequently asked questions

What is CVE-2026-43097?
In the Linux kernel, the following vulnerability has been resolved: PCI: hv: Fix double ida_free in hv_pci_probe error path If hv_pci_probe() fails after storing the domain number in hbus->bridge->domain_nr, there is a call to free this domain_nr via pci_bus_release_emul_domain_nr(), however, during cleanup, the bridge release callback pci_release_host_bridge_dev() also frees the domain_nr causing ida_free to be called on same ID twice and triggering following warning: ida_free called for id=28971 which is not allocated. WARNING: lib/idr.c:594 at ida_free+0xdf/0x160, CPU#0: kworker/0:2/198 Call Trace: pci_bus_release_emul_domain_nr+0x17/0x20 pci_release_host_bridge_dev+0x4b/0x60 device_release+0x3b/0xa0 kobject_put+0x8e/0x220 devm_pci_alloc_host_bridge_release+0xe/0x20 devres_release_all+0x9a/0xd0 device_unbind_cleanup+0x12/0xa0 really_probe+0x1c5/0x3f0 vmbus_add_channel_work+0x135/0x1a0 Fix this by letting pci core handle the free domain_nr and remove the explicit free called in pci-hyperv driver.
How severe is CVE-2026-43097?
CVE-2026-43097 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-43097 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43097?
CVE-2026-43097 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43097?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-43097 have an EU (EUVD) identifier?
Yes. CVE-2026-43097 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27604.
When was CVE-2026-43097 published?
CVE-2026-43097 was published on 2026-05-06 and last updated on 2026-06-17.

References

Affected products (8)

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