CVE-2026-64296exfat: bound uniname advance in exfat_find_dir_entry()
- 7.8HighCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < 72a2589d82eb001c94b74bcfe6f9a599bd9bef60
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < cf85180b8a015029ee147694eaf4e0b3537e9432
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < 727bf7783a2936ffd55c628dddfd69343e511dcf
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < 33c0b96d7e1672be1de0053786637ea46fb81507
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < c8e041c68c0bbb73aa62371ee63947bb6949d8b2
- affected ca06197382bde0a3bc20215595d1c9ce20c6e341 – < 3a1230e7b043c62737b05a3e9275ca83a43ad20a
- affected 5.7
- unaffected < 5.7
- unaffected 5.10.261 – ≤ 5.10.*
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.96 – ≤ 6.12.*
- unaffected 6.18.39 – ≤ 6.18.*
- unaffected 7.1.4 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References8
- https://git.kernel.org/stable/c/72a2589d82eb001c94b74bcfe6f9a599bd9bef60 (opens in a new tab)
- https://git.kernel.org/stable/c/fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4 (opens in a new tab)
- https://git.kernel.org/stable/c/cf85180b8a015029ee147694eaf4e0b3537e9432 (opens in a new tab)
- https://git.kernel.org/stable/c/ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0 (opens in a new tab)
- https://git.kernel.org/stable/c/727bf7783a2936ffd55c628dddfd69343e511dcf (opens in a new tab)
- https://git.kernel.org/stable/c/33c0b96d7e1672be1de0053786637ea46fb81507 (opens in a new tab)
- https://git.kernel.org/stable/c/c8e041c68c0bbb73aa62371ee63947bb6949d8b2 (opens in a new tab)
- https://git.kernel.org/stable/c/3a1230e7b043c62737b05a3e9275ca83a43ad20a (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-49008 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-64296)Record last updated .