CVE-2026-80861 — usb: xhci: bail out of setup if the controller is inaccessible
In the Linux kernel, the following vulnerability has been resolved: usb: xhci: bail out of setup if the controller is inaccessible xhci_gen_setup() locates the operational registers using the capability length read from the very first register: xhci->op_regs = hcd->regs + HC_LENGTH(readl(&xhci->cap_regs->hc_capbase)); If the controller is dead or has dropped off the bus, that read returns ~0, HC_LENGTH() truncates it to 0xff, and op_regs ends up 0xff bytes past the page-aligned MMIO base, i.e. unaligned. The first access through it, xhci_halt() -> xhci_handshake() reading op_regs->status, is then an unaligned readl() on device memory. arm64 faults on unaligned device accesses, so instead of xhci_handshake() catching the all-ones value and returning -ENODEV, setup oopses: xhci-pci-renesas 0005:08:00.0: Unable to change power state from D3cold to D0, device inaccessible xhci-pci-renesas 0005:08:00.0: xHCI Host Controller xhci-pci-renesas 0005:08:00.0: new USB bus registered, assigned bus number 1 Unable to handle kernel paging request at virtual address ffff80030a770103 ESR = 0x0000000096000021 FSC = 0x21: alignment fault Internal error: Oops: 0000000096000021 [#1] SMP pc : xhci_halt [xhci_hcd] Call trace: xhci_halt xhci_gen_setup xhci_pci_setup usb_add_hcd usb_hcd_pci_probe xhci_pci_common_probe xhci_pci_renesas_probe This was hit with a Renesas uPD720201 that failed to power up ("Unable to change power state from D3cold to D0, device inaccessible") yet still reached the HCD probe path. Read the capability register once, and if it reads back the all-ones value (as xhci_handshake() and xhci_reset() already test for), abort setup with -ENODEV before op_regs is derived from it. Reading it once also avoids re-reading a register that may change under a concurrent hot-removal.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < 301f4a3303b21ea959a8294518ee883710498ac2≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < 70706dbcf122940f4e3595d7ba1445004cc00074≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < c051f66b621695ad7c8438a9497d79e1f4f05edb≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < bf84c6b0264947794fa783c324a6d874ca6657d8≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < 0b31744f70c5e06cce5fb660e02d057a3b9e0e37≥ 66d4eadd8d067269ea8fead1a50fe87c2979a80d and < 78203d5b54a40f0e36196ebf31c9c7a380fc8811version 2.6.31 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 26, 2026 · 11 reading(s) · max 0.16%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- nvd.nist.gov/vuln/detail/CVE-2026-80861
- git.kernel.org/stable/c/0b31744f70c5e06cce5fb660e02d057a3b9e0e37
- git.kernel.org/stable/c/301f4a3303b21ea959a8294518ee883710498ac2
- git.kernel.org/stable/c/70706dbcf122940f4e3595d7ba1445004cc00074
- git.kernel.org/stable/c/78203d5b54a40f0e36196ebf31c9c7a380fc8811
- git.kernel.org/stable/c/c051f66b621695ad7c8438a9497d79e1f4f05edb
- github.com/advisories/GHSA-8wxp-3ggp-2gcw
- git.kernel.org/stable/c/bf84c6b0264947794fa783c324a6d874ca6657d8
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99092 riscv: patch: fix handling of bpf-jit execmem addresses 15h
- Unknown CVE-2026-99093 mm: don't schedule deferred kernel page table freeing while booting 15h
- Unknown CVE-2026-99095 drm/vc4: drain the hangcheck timer and works on V3D unbind 15h
- Unknown CVE-2026-99096 io_uring/register: don't exempt disabled rings from task restrictions 15h
- Unknown CVE-2026-99097 tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper() 15h
- Unknown CVE-2026-99098 dm-integrity: fix buffer overflow in inline mode with large tag size 15h
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-80861 is "usb: xhci: bail out of setup if the controller is inaccessible", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.16% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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