CVE-2026-43424 — usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling The `tpg->tpg_nexus` pointer in the USB Target driver is dynamically managed and tied to userspace configuration via ConfigFS. It can be NULL if the USB host sends requests before the nexus is fully established or immediately after it is dropped. Currently, functions like `bot_submit_command()` and the data transfer paths retrieve `tv_nexus = tpg->tpg_nexus` and immediately dereference `tv_nexus->tvn_se_sess` without any validation. If a malicious or misconfigured USB host sends a BOT (Bulk-Only Transport) command during this race window, it triggers a NULL pointer dereference, leading to a kernel panic (local DoS). This exposes an inconsistent API usage within the module, as peer functions like `usbg_submit_command()` and `bot_send_bad_response()` correctly implement a NULL check for `tv_nexus` before proceeding. Fix this by bringing consistency to the nexus handling. Add the missing `if (!tv_nexus)` checks to the vulnerable BOT command and request processing paths, aborting the command gracefully with an error instead of crashing the system.
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
- Technical severity (medium)+3
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.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
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, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | version 3.5≥ c52661d60f636d17e26ad834457db333bd1df494 and < b9fde507355342a2d64225d582dc8b98ff5ecb19≥ c52661d60f636d17e26ad834457db333bd1df494 and < 3d309b37633c4a847fc149939a2c9576f1aa1065≥ c52661d60f636d17e26ad834457db333bd1df494 and < 679d9535aeb15c10bce89c44102004b96624d706≥ c52661d60f636d17e26ad834457db333bd1df494 and < f962ca3b020e13d6714f27e8c36fe742441c58d1≥ c52661d60f636d17e26ad834457db333bd1df494 and < d146f27758049fa55ae4c53785a852d3cf7a18d6≥ c52661d60f636d17e26ad834457db333bd1df494 and < 2a2ef846a54a06c33b5c2d4b0d918583e1e7c0b7≥ c52661d60f636d17e26ad834457db333bd1df494 and < b9b26d7f3aa288cfa54a7bc68612bab1f153f156 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 7.0-rc4≥ 3.5 and < 5.10.253version 7.0-rc3version 7.0-rc2version 7.0-rc1≥ 6.19 and < 6.19.9≥ 6.13 and < 6.18.19≥ 6.7 and < 6.12.78 and 2 more≥ 6.2 and < 6.6.130≥ 5.11 and < 6.1.167 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.16%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
7 on the record
- git.kernel.org/stable/c/d146f27758049fa55ae4c53785a852d3cf7a18d6
- git.kernel.org/stable/c/3d309b37633c4a847fc149939a2c9576f1aa1065
- git.kernel.org/stable/c/b9b26d7f3aa288cfa54a7bc68612bab1f153f156
- git.kernel.org/stable/c/679d9535aeb15c10bce89c44102004b96624d706
- git.kernel.org/stable/c/b9fde507355342a2d64225d582dc8b98ff5ecb19
- git.kernel.org/stable/c/f962ca3b020e13d6714f27e8c36fe742441c58d1
- git.kernel.org/stable/c/2a2ef846a54a06c33b5c2d4b0d918583e1e7c0b7
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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 CISA SSVC assessment.
- 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-2026-43424 is "usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. 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.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.