In the Linux kernel, the following vulnerability has been resolved:
PCI: pciehp: Avoid unnecessary device replacement check
Hot-removal of nested PCI hotplug ports suffers from a long-standing race
condition which can lead to a deadlock: A parent hotplug port acquires
pci_lock_rescan_remove(), then waits for pciehp to unbind from a child
hotplug port. Meanwhile that child hotplug port tries to acquire
pci_lock_rescan_remove() as well in order to remove its own children.
The deadlock only occurs if the parent acquires pci_lock_rescan_remove()
first, not if the child happens to acquire it first.
Several workarounds to avoid the issue have been proposed and discarded
over the years, e.g.:
https://lore.kernel.org/r/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/
A proper fix is being worked on, but needs more time as it is nontrivial
and necessarily intrusive.
Recent commit 9d573d19547b ("PCI: pciehp: Detect device replacement during
system sleep") provokes more frequent occurrence of the deadlock when
removing more than one Thunderbolt device during system sleep. The commit
sought to detect device replacement, but also triggered on device removal.
Differentiating reliably between replacement and removal is impossible
because pci_get_dsn() returns 0 both if the device was removed, as well as
if it was replaced with one lacking a Device Serial Number.
Avoid the more frequent occurrence of the deadlock by checking whether the
hotplug port itself was hot-removed. If so, there's no sense in checking
whether its child device was replaced.
This works because the ->resume_noirq() callback is invoked in top-down
order for the entire hierarchy: A parent hotplug port detecting device
replacement (or removal) marks all children as removed using
pci_dev_set_disconnected() and a child hotplug port can then reliably
detect being removed.
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 low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 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 low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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)14 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's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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