Description
Zephyr's ext2 directory-entry parser does not fully validate on-disk directory entry structure before copying the entry name and advancing traversal state. In ext2_fetch_direntry() (subsys/fs/ext2/ext2_diskops.c), the code only checks de_name_len <= EXT2_MAX_FILE_NAME and then copies the name with memcpy without validating the structural relationship between de_rec_len, de_name_len, and the directory block boundary (for example that de_rec_len is non-zero, at least the size of the entry header, and that the record fits within the block). Callers such as find_dir_entry() and ext2_get_direntry() (subsys/fs/ext2/ext2_impl.c) then advance traversal using the unvalidated de_rec_len. A crafted ext2 image can therefore cause an out-of-bounds read from the directory block buffer when a malformed entry near the end of a block triggers an oversized name copy, or a zero-progress infinite loop when de_rec_len == 0. The issue is not reached at mount time but later through directory traversal paths such as pathname lookup, stat/open/unlink/rename, and readdir. The primary impact is denial of service and out-of-bounds reads under attacker-controlled ext2 images mounted from untrusted media.
Published: 2026-06-22
Score: 4.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Tue, 23 Jun 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 23 Jun 2026 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Zephyrproject-rtos
Zephyrproject-rtos zephyr
Vendors & Products Zephyrproject-rtos
Zephyrproject-rtos zephyr

Tue, 23 Jun 2026 00:30:00 +0000

Type Values Removed Values Added
Description Zephyr's ext2 directory-entry parser does not fully validate on-disk directory entry structure before copying the entry name and advancing traversal state. In ext2_fetch_direntry() (subsys/fs/ext2/ext2_diskops.c), the code only checks de_name_len <= EXT2_MAX_FILE_NAME and then copies the name with memcpy without validating the structural relationship between de_rec_len, de_name_len, and the directory block boundary (for example that de_rec_len is non-zero, at least the size of the entry header, and that the record fits within the block). Callers such as find_dir_entry() and ext2_get_direntry() (subsys/fs/ext2/ext2_impl.c) then advance traversal using the unvalidated de_rec_len. A crafted ext2 image can therefore cause an out-of-bounds read from the directory block buffer when a malformed entry near the end of a block triggers an oversized name copy, or a zero-progress infinite loop when de_rec_len == 0. The issue is not reached at mount time but later through directory traversal paths such as pathname lookup, stat/open/unlink/rename, and readdir. The primary impact is denial of service and out-of-bounds reads under attacker-controlled ext2 images mounted from untrusted media.
Title fs: ext2: Missing structural validation of directory entries can cause out-of-bounds read and zero-progress directory traversal
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H'}


Subscriptions

Zephyrproject-rtos Zephyr
cve-icon MITRE

Status: PUBLISHED

Assigner: zephyr

Published:

Updated: 2026-06-23T12:22:04.925Z

Reserved: 2026-06-02T15:11:47.668Z

Link: CVE-2026-10645

cve-icon Vulnrichment

Updated: 2026-06-23T12:22:00.484Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-23T02:30:16Z

Weaknesses