{"api_version":"1","generated_at":"2026-10-29T09:56:05+00:00","cve":"CVE-2026-14986","urls":{"html":"https://cve.report/CVE-2026-14986","api":"https://cve.report/api/cve/CVE-2026-14986.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-14986","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-14986"},"summary":{"title":"Out-of-bounds write in it51xxx I2C target FIFO ISR on oversized write transaction","description":"The ITE it51xxx I2C driver, when operating as an I2C target (slave) in buffer mode (CONFIG_I2C_TARGET + CONFIG_I2C_TARGET_BUFFER_MODE), copies host-supplied write data into the fixed-size data->target_in_buffer inside its target FIFO interrupt handler target_i2c_isr_fifo() in drivers/i2c/i2c_ite_it51xxx.c. The copy loop stores to target_in_buffer[i + data->w_index] and only checks data->w_index against sizeof(data->target_in_buffer) after the write has already completed, so the bounds check cannot prevent the overflow.\n\nThe running index data->w_index accumulates count bytes on every FIFO-fill interrupt of an ongoing transaction and is reset to zero only on a STOP or timeout condition. An I2C host that streams a single write transaction longer than the buffer (default CONFIG_I2C_TARGET_IT51XXX_MAX_BUF_SIZE = 256 bytes) drives data->w_index past the end of the buffer, and each subsequent host byte is written out of bounds into the adjacent data->target_out_buffer and following static device data.\n\nThe trigger is a malicious or misbehaving I2C master on the same bus (for example a compromised application processor or a rogue device on an exposed I2C bus); no software privilege on the victim is required and the handler runs in the target's kernel/firmware context. Because both the written values and the overflow length are attacker-controlled, this is an out-of-bounds write that can crash the controller or be shaped toward code execution. The fix adds a pre-write bounds check in target_i2c_fifo_read_to_buf() that aborts and resets the FIFO before any out-of-bounds store.","state":"PUBLISHED","assigner":"zephyr","published_at":"2026-09-14 23:17:15","updated_at":"2026-09-18 19:11:57"},"problem_types":["CWE-787","CWE-787 bounds"],"metrics":[{"version":"3.1","source":"vulnerabilities@zephyrproject.org","type":"Secondary","score":"6.8","severity":"MEDIUM","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":6.8,"baseSeverity":"MEDIUM","attackVector":"PHYSICAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"6.8","severity":"MEDIUM","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":6.8,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/eac92173cf13bba4e6c6eea3460ee6085513d86d","name":"https://github.com/zephyrproject-rtos/zephyr/commit/eac92173cf13bba4e6c6eea3460ee6085513d86d","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-jmjj-w736-fw2j","name":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-jmjj-w736-fw2j","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-14986","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-14986","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 4.2.0 4.4.2 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"14986","cve":"CVE-2026-14986","epss":"0.001820000","percentile":"0.080600000","score_date":"2026-09-21","updated_at":"2026-09-22 00:03:18"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-14986","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2026-09-15T13:42:52.993721Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-15T13:43:00.316Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["drivers/i2c/Kconfig.it51xxx","drivers/i2c/i2c_ite_it51xxx.c"],"programRoutines":[{"name":"target_i2c_isr_fifo"}],"vendor":"zephyrproject","versions":[{"lessThan":"4.4.2","status":"affected","version":"4.2.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"The ITE it51xxx I2C driver, when operating as an I2C target (slave) in buffer mode (CONFIG_I2C_TARGET + CONFIG_I2C_TARGET_BUFFER_MODE), copies host-supplied write data into the fixed-size data->target_in_buffer inside its target FIFO interrupt handler target_i2c_isr_fifo() in drivers/i2c/i2c_ite_it51xxx.c. The copy loop stores to target_in_buffer[i + data->w_index] and only checks data->w_index against sizeof(data->target_in_buffer) after the write has already completed, so the bounds check cannot prevent the overflow.\n\nThe running index data->w_index accumulates count bytes on every FIFO-fill interrupt of an ongoing transaction and is reset to zero only on a STOP or timeout condition. An I2C host that streams a single write transaction longer than the buffer (default CONFIG_I2C_TARGET_IT51XXX_MAX_BUF_SIZE = 256 bytes) drives data->w_index past the end of the buffer, and each subsequent host byte is written out of bounds into the adjacent data->target_out_buffer and following static device data.\n\nThe trigger is a malicious or misbehaving I2C master on the same bus (for example a compromised application processor or a rogue device on an exposed I2C bus); no software privilege on the victim is required and the handler runs in the target's kernel/firmware context. Because both the written values and the overflow length are attacker-controlled, this is an out-of-bounds write that can crash the controller or be shaped toward code execution. The fix adds a pre-write bounds check in target_i2c_fifo_read_to_buf() that aborts and resets the FIFO before any out-of-bounds store."}],"metrics":[{"cvssV3_1":{"baseScore":6.8,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","description":"bounds","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-14T22:07:46.392Z","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr"},"references":[{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/eac92173cf13bba4e6c6eea3460ee6085513d86d"},{"name":"GHSA-jmjj-w736-fw2j","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-jmjj-w736-fw2j"}],"title":"Out-of-bounds write in it51xxx I2C target FIFO ISR on oversized write transaction","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","assignerShortName":"zephyr","cveId":"CVE-2026-14986","datePublished":"2026-09-14T22:07:46.392Z","dateReserved":"2026-07-07T18:24:46.814Z","dateUpdated":"2026-09-15T13:43:00.316Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-14 23:17:15","lastModifiedDate":"2026-09-18 19:11:57","problem_types":["CWE-787","CWE-787 bounds"],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":6.8,"baseSeverity":"MEDIUM","attackVector":"PHYSICAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":0.9,"impactScore":5.9}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-15T13:42:52.993721Z","id":"CVE-2026-14986","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"14986","Ordinal":"1","Title":"Out-of-bounds write in it51xxx I2C target FIFO ISR on oversized ","CVE":"CVE-2026-14986","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"14986","Ordinal":"1","NoteData":"The ITE it51xxx I2C driver, when operating as an I2C target (slave) in buffer mode (CONFIG_I2C_TARGET + CONFIG_I2C_TARGET_BUFFER_MODE), copies host-supplied write data into the fixed-size data->target_in_buffer inside its target FIFO interrupt handler target_i2c_isr_fifo() in drivers/i2c/i2c_ite_it51xxx.c. The copy loop stores to target_in_buffer[i + data->w_index] and only checks data->w_index against sizeof(data->target_in_buffer) after the write has already completed, so the bounds check cannot prevent the overflow.\n\nThe running index data->w_index accumulates count bytes on every FIFO-fill interrupt of an ongoing transaction and is reset to zero only on a STOP or timeout condition. An I2C host that streams a single write transaction longer than the buffer (default CONFIG_I2C_TARGET_IT51XXX_MAX_BUF_SIZE = 256 bytes) drives data->w_index past the end of the buffer, and each subsequent host byte is written out of bounds into the adjacent data->target_out_buffer and following static device data.\n\nThe trigger is a malicious or misbehaving I2C master on the same bus (for example a compromised application processor or a rogue device on an exposed I2C bus); no software privilege on the victim is required and the handler runs in the target's kernel/firmware context. Because both the written values and the overflow length are attacker-controlled, this is an out-of-bounds write that can crash the controller or be shaped toward code execution. The fix adds a pre-write bounds check in target_i2c_fifo_read_to_buf() that aborts and resets the FIFO before any out-of-bounds store.","Type":"Description","Title":"Out-of-bounds write in it51xxx I2C target FIFO ISR on oversized "}]}}}