CVE-2026-80923 — xhci: dbgtty: Fix unregister on tty_register_driver() failure
In the Linux kernel, the following vulnerability has been resolved: xhci: dbgtty: Fix unregister on tty_register_driver() failure If tty_register_driver() fails, it drops the reference, but fails to set the global dbc_tty_driver to NULL, causing the unregister to be called again when module exits. On module unload dbc_tty_exit() only gates its cleanup on the driver pointer being non-NULL, so it operates on the already-freed driver: module_init(xhci_hcd_init) xhci_hcd_init() xhci_dbc_init() [return value ignored] dbc_tty_init() tty_register_driver() fails tty_driver_kref_put() -> driver freed (dbc_tty_driver left dangling) ... module_exit(xhci_hcd_fini) xhci_hcd_fini() xhci_dbc_exit() dbc_tty_exit() if (dbc_tty_driver) -> true (dangling) tty_unregister_driver() -> use-after-free
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 |
≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 01b7bc0938061f2fd46e0094f6483d8c6c02f7d3≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 43635ff6401ca0e0ed21875379eeded921321525≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < eaca2814f32b9872a332326324b9e83e01f156d2≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 943f976c93e70563b132f5585ff68b08c89641a2≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 0d0faf3cc44c4d86fc6faf5cea972c0fbe00b922≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 33ed35ca629477f57e0dd1d77d6df96cf5a9eb55≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < 0e469b94fbba8eb03666da41dd1082b793c50c1a≥ 4521f16139409cdf9462c7325d43454462cff6c3 and < a916fa66a43e10f63198b6ce978badffc678821a and 1 moreversion 5.9 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 28, 2026 · 13 reading(s) · max 0.17%
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
10 on the record
- git.kernel.org/stable/c/a916fa66a43e10f63198b6ce978badffc678821a
- git.kernel.org/stable/c/0e469b94fbba8eb03666da41dd1082b793c50c1a
- git.kernel.org/stable/c/0d0faf3cc44c4d86fc6faf5cea972c0fbe00b922
- github.com/advisories/GHSA-m8fv-jwwg-rhrm
- git.kernel.org/stable/c/943f976c93e70563b132f5585ff68b08c89641a2
- git.kernel.org/stable/c/eaca2814f32b9872a332326324b9e83e01f156d2
- git.kernel.org/stable/c/01b7bc0938061f2fd46e0094f6483d8c6c02f7d3
- nvd.nist.gov/vuln/detail/CVE-2026-80923
- git.kernel.org/stable/c/33ed35ca629477f57e0dd1d77d6df96cf5a9eb55
- git.kernel.org/stable/c/43635ff6401ca0e0ed21875379eeded921321525
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 1d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 1d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 1d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 1d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 1d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 1d
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-2026-80923 is "xhci: dbgtty: Fix unregister on tty_register_driver() failure", 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 0.17% 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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