{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-7007", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-04-24T22:00:52.689Z", "datePublished": "2026-07-24T13:48:24.831Z", "dateUpdated": "2026-07-24T15:04:01.152Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-07-24T13:48:24.831Z"}, "title": "Division by zero in Zephyr ext2 superblock parsing allows DoS via crafted filesystem image", "descriptions": [{"lang": "en", "value": "The Zephyr ext2 file system validates the on-disk superblock in ext2_verify_disk_superblock() (subsys/fs/ext2/ext2_impl.c) before completing a mount. The validator checked the magic number, block size, revision and feature flags, but did not verify that the on-disk fields s_blocks_per_group and s_inodes_per_group are non-zero. Both fields are read directly from the image and are later used as divisors during mount-time initialization.\n\nDuring mount, get_ngroups() divides and modulos s_blocks_count by s_blocks_per_group (reached via ext2_fetch_block_group() from ext2_init_fs()), and get_itable_entry() divides (ino - 1) by s_inodes_per_group when fetching the root inode (both in subsys/fs/ext2/ext2_diskops.c). A superblock with either field set to zero therefore causes an integer division by zero during the mount sequence.\n\nAn attacker who can present a crafted ext2 image to a device that mounts ext2 \u2014 removable media such as an SD card or a USB mass-storage device \u2014 can trigger this. On ARMv7-M / ARMv8-M-mainline Cortex-M targets, divide-by-zero trapping is enabled (SCB_CCR_DIV_0_TRP), so the division raises a UsageFault that Zephyr treats as a fatal error, producing a denial of service. The impact is limited to availability; the malformed value is consumed only as a divisor.\n\nThe fix rejects a zero s_blocks_per_group or s_inodes_per_group in the superblock validator, returning -EINVAL so the mount fails before any block-group or inode I/O occurs."}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": ["subsys/fs/ext2/ext2_impl.c"], "versions": [{"version": "3.5.0", "status": "affected", "lessThan": "4.5.0", "versionType": "semver"}]}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/babc0900ed40e6c023ccc26aa1a321f9388b66af", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wrf2-79mm-cvw5", "name": "GHSA-wrf2-79mm-cvw5"}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.6, "baseSeverity": "MEDIUM"}}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "dos", "cweId": "CWE-369", "type": "CWE"}]}], "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-369", "lang": "en", "description": "CWE-369 Divide By Zero"}]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-07-24T15:03:26.497157Z", "id": "CVE-2026-7007", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-24T15:04:01.152Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-7007", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-24T15:03:26.497157Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-369", "description": "CWE-369 Divide By Zero"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-24T15:03:52.291Z"}}], "cna": {"title": "Division by zero in Zephyr ext2 superblock parsing allows DoS via crafted filesystem image", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 4.6, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "versions": [{"status": "affected", "version": "3.5.0", "lessThan": "4.5.0", "versionType": "semver"}], "packageName": "zephyr", "programFiles": ["subsys/fs/ext2/ext2_impl.c"], "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected"}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/babc0900ed40e6c023ccc26aa1a321f9388b66af", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wrf2-79mm-cvw5", "name": "GHSA-wrf2-79mm-cvw5"}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "The Zephyr ext2 file system validates the on-disk superblock in ext2_verify_disk_superblock() (subsys/fs/ext2/ext2_impl.c) before completing a mount. The validator checked the magic number, block size, revision and feature flags, but did not verify that the on-disk fields s_blocks_per_group and s_inodes_per_group are non-zero. Both fields are read directly from the image and are later used as divisors during mount-time initialization.\n\nDuring mount, get_ngroups() divides and modulos s_blocks_count by s_blocks_per_group (reached via ext2_fetch_block_group() from ext2_init_fs()), and get_itable_entry() divides (ino - 1) by s_inodes_per_group when fetching the root inode (both in subsys/fs/ext2/ext2_diskops.c). A superblock with either field set to zero therefore causes an integer division by zero during the mount sequence.\n\nAn attacker who can present a crafted ext2 image to a device that mounts ext2 \u2014 removable media such as an SD card or a USB mass-storage device \u2014 can trigger this. On ARMv7-M / ARMv8-M-mainline Cortex-M targets, divide-by-zero trapping is enabled (SCB_CCR_DIV_0_TRP), so the division raises a UsageFault that Zephyr treats as a fatal error, producing a denial of service. The impact is limited to availability; the malformed value is consumed only as a divisor.\n\nThe fix rejects a zero s_blocks_per_group or s_inodes_per_group in the superblock validator, returning -EINVAL so the mount fails before any block-group or inode I/O occurs."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-369", "description": "dos"}]}], "providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-07-24T13:48:24.831Z"}}}, "cveMetadata": {"cveId": "CVE-2026-7007", "state": "PUBLISHED", "dateUpdated": "2026-07-24T15:04:01.152Z", "dateReserved": "2026-04-24T22:00:52.689Z", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "datePublished": "2026-07-24T13:48:24.831Z", "assignerShortName": "zephyr"}, "dataVersion": "5.2"}

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