CVE-2026-80861
Vulnerability Scoring
Status: Received on 04 Sep 2026, 16:18 UTC
Last updated: 🕙 11 Sep 2026, 10:16 UTC
Originally published on: 🕓 04 Sep 2026, 16:18 UTC
Time between publication and last update: 6 days
CVSS Release:
CVE-2026-80861: 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.
The exploitability of CVE-2026-80861 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
No exploitability data is available for CVE-2026-80861.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-80861, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-80861, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
Unknown
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