In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix freeing of uninitialized misc IRQ vector
When VSI set up failed in i40e_probe() as part of PF switch set up
driver was trying to free misc IRQ vectors in
i40e_clear_interrupt_scheme and produced a kernel Oops:
Trying to free already-free IRQ 266
WARNING: CPU: 0 PID: 5 at kernel/irq/manage.c:1731 __free_irq+0x9a/0x300
Workqueue: events work_for_cpu_fn
RIP: 0010:__free_irq+0x9a/0x300
Call Trace:
? synchronize_irq+0x3a/0xa0
free_irq+0x2e/0x60
i40e_clear_interrupt_scheme+0x53/0x190 [i40e]
i40e_probe.part.108+0x134b/0x1a40 [i40e]
? kmem_cache_alloc+0x158/0x1c0
? acpi_ut_update_ref_count.part.1+0x8e/0x345
? acpi_ut_update_object_reference+0x15e/0x1e2
? strstr+0x21/0x70
? irq_get_irq_data+0xa/0x20
? mp_check_pin_attr+0x13/0xc0
? irq_get_irq_data+0xa/0x20
? mp_map_pin_to_irq+0xd3/0x2f0
? acpi_register_gsi_ioapic+0x93/0x170
? pci_conf1_read+0xa4/0x100
? pci_bus_read_config_word+0x49/0x70
? do_pci_enable_device+0xcc/0x100
local_pci_probe+0x41/0x90
work_for_cpu_fn+0x16/0x20
process_one_work+0x1a7/0x360
worker_thread+0x1cf/0x390
? create_worker+0x1a0/0x1a0
kthread+0x112/0x130
? kthread_flush_work_fn+0x10/0x10
ret_from_fork+0x1f/0x40
The problem is that at that point misc IRQ vectors
were not allocated yet and we get a call trace
that driver is trying to free already free IRQ vectors.
Add a check in i40e_clear_interrupt_scheme for __I40E_MISC_IRQ_REQUESTED
PF state before calling i40e_free_misc_vector. This state is set only if
misc IRQ vectors were properly initialized.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it