CVE-2026-64296exfat: bound uniname advance in exfat_find_dir_entry()
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In the Linux kernel, the following vulnerability has been resolved: exfat: bound uniname advance in exfat_find_dir_entry() In exfat_find_dir_entry(), each TYPE_EXTEND (file name) entry advances the output pointer by a fixed amount while the loop guard only tracks the accumulated name length: if (++order == 2) uniname = p_uniname->name; else uniname += EXFAT_FILE_NAME_LEN; len = exfat_extract_uni_name(ep, entry_uniname); name_len += len; unichar = *(uniname+len); *(uniname+len) = 0x0; uniname grows by EXFAT_FILE_NAME_LEN (15) per name entry, but name_len grows only by the actual extracted length, which is shorter when a name fragment contains an early NUL. The only guard is `name_len >= MAX_NAME_LENGTH`, so a crafted directory with many short name fragments lets uniname run far past the p_uniname->name[MAX_NAME_LENGTH + 3] buffer while name_len stays small, causing an out-of-bounds read and write at *(uniname+len). The sibling extractor exfat_get_uniname_from_ext_entry() already stops on a short fragment (the lockstep `len != EXFAT_FILE_NAME_LEN` guard added in commit d42334578eba ("exfat: check if filename entries exceeds max filename length")); exfat_find_dir_entry() never got the equivalent. Track the per-entry write offset as a count and reject a fragment once the offset, or the offset plus the extracted length, would exceed MAX_NAME_LENGTH, before forming the output pointer.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from ca06197382bde0a3bc20215595d1c9ce20c6e341 before 72a2589d82eb001c94b74bcfe6f9a599bd9bef60; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before cf85180b8a015029ee147694eaf4e0b3537e9432; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before 727bf7783a2936ffd55c628dddfd69343e511dcf; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before 33c0b96d7e1672be1de0053786637ea46fb81507; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before c8e041c68c0bbb73aa62371ee63947bb6949d8b2; from ca06197382bde0a3bc20215595d1c9ce20c6e341 before 3a1230e7b043c62737b05a3e9275ca83a43ad20a | CNA record |
linux linux_kernel linux:linux_kernel | from 5.7 before 5.10.261; from 5.11 before 5.15.212; from 5.16 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.4 | NVD |
References
- https://git.kernel.org/stable/c/72a2589d82eb001c94b74bcfe6f9a599bd9bef60patch
- https://git.kernel.org/stable/c/fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4patch
- https://git.kernel.org/stable/c/cf85180b8a015029ee147694eaf4e0b3537e9432patch
- https://git.kernel.org/stable/c/ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0patch
- https://git.kernel.org/stable/c/727bf7783a2936ffd55c628dddfd69343e511dcfpatch
- https://git.kernel.org/stable/c/33c0b96d7e1672be1de0053786637ea46fb81507patch
- https://git.kernel.org/stable/c/c8e041c68c0bbb73aa62371ee63947bb6949d8b2patch
- https://git.kernel.org/stable/c/3a1230e7b043c62737b05a3e9275ca83a43ad20apatch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.