CVE-2026-10683 — DesignWare I2C target driver can be wedged into a permanent stuck state by an on-bus master (DoS)
In the Synopsys DesignWare I2C driver (drivers/i2c/i2c_dw.c) operating in target/slave mode, the rx_full interrupt handler gates the write_requested() callback on dw->state != CMD_SEND, and dw->state is only reset to READY on a STOP interrupt. The START_DET interrupt, whose handler in i2c_dw_slave_read_clear_intr_bits() would reset the state on every (re)START, was never added to the enabled interrupt mask in i2c_dw_slave_register(), so that recovery path was dead code. As a result, if the STOP interrupt is lost (bus glitch/reset, or a concurrent master driving STOP) or the bus master issues a legal WRITE-repeated-START-WRITE sequence with the same direction, the driver remains in CMD_SEND permanently and never invokes write_requested() again for the life of the target. An I2C master on the same physical bus can deliberately trigger this, causing the I2C target function to malfunction for all subsequent write transactions and desynchronizing consumer framing state (e.g. MCTP-over-I2C), a recoverable-by-reset denial of service of the target peripheral. The fix unmasks START_DET so the state is reset at every bus (re)START. Impact is availability-only over a local board-level bus; no memory corruption results in the in-tree consumer, whose per-byte buffer write is independently bounds-checked.
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
- 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.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (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 (Zephyrproject Zephyr).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Zephyrproject | Zephyr | ≥ 4.0.0 and < 4.5.0 | Vulnerable | NIST National Vulnerability Database |
| Zephyrproject | Zephyr | ≥ 4.0.0 and < 4.4.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
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 |
|---|---|---|---|---|---|
| 4.6 | CVSS 3.1 | Medium | 0.9 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 2.4 | CVSS 3.1 | Low | 0.9 | 1.4 | vulnerabilities@zephyrproject.org via NIST National Vulnerability Database |
| 2.4 | CVSS 3.1 | Low | — | — | zephyr via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:P/AC:L/PR:N/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.
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.
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · zephyrproject/zephyr
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 4.6
- 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 15, 2026 – Oct 15, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
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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 FIRST EPSS score.
- 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-2026-10683 is "DesignWare I2C target driver can be wedged into a permanent stuck state by an on-bus master (DoS)", rated Medium. It affects Zephyr (Zephyrproject); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.6 describes technical severity. 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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