Linux Kernel up to 7.2.5 NTFS3 fs/ntfs3/fslog.c alloc_rsttbl_from_idx use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.0$5k-$25k0.00

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 7.2.5. This vulnerability affects the function alloc_rsttbl_from_idx of the file fs/ntfs3/fslog.c of the component NTFS3. Executing a manipulation can lead to use after free. This vulnerability is tracked as CVE-2026-89782. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.2.5 and classified as very critical. This vulnerability affects the function alloc_rsttbl_from_idx of the file fs/ntfs3/fslog.c of the component NTFS3. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: reject restart table growth beyond U16_MAX entries During $LogFile replay, log_replay() indexes the transaction table by the transact_id taken from the log record header. check_log_rec() only verifies that transact_id is non-zero and properly aligned, not its magnitude, so a crafted image can request an arbitrarily large index. alloc_rsttbl_from_idx() grows the table to cover that index via extend_rsttbl(), which passes the new entry count to init_rsttbl(): rt = init_rsttbl(esize, used + add); used + add is computed as u32 but init_rsttbl() takes a u16, and the count is stored in struct RESTART_TABLE as a __le16. When used + add exceeds U16_MAX it is truncated, init_rsttbl() allocates a table far smaller than the index requires, and alloc_rsttbl_from_idx() then dereferences and writes at the original, untruncated offset -- an out-of-bounds access past the allocation, reachable by mounting a crafted NTFS image. BUG: KASAN: use-after-free in alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) Read of size 4 at addr ffff8880327ffff8 by task exploit alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) log_replay (fs/ntfs3/fslog.c:4562) ntfs_loadlog_and_replay (fs/ntfs3/fsntfs.c:324) ntfs_fill_super (fs/ntfs3/super.c:1393) get_tree_bdev_flags vfs_get_tree path_mount __x64_sys_mount A restart table is limited to U16_MAX entries by its __le16 count, so a larger growth request is invalid input. Reject it in extend_rsttbl(); all callers already handle a NULL return.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-89782 since 09/11/2026. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56/339e59996ff193adcf1c438cf05f19e753beb3a7/ecde45cd81dc28f5696c312c5ce5a509962e9ab1/be218a01aadffe33ed4fc73e25276d676ebbd09d/aad605a450611e2a7b7cf9dd5724004d39192bfb/967a5ff8a614d10126b6d46db1ac040948d6cb42/111f8d74a19d85942ecbb3aba78f6f3c88e59391 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.4
VulDB Meta Temp Score: 8.0

VulDB Base Score: 8.4
VulDB Temp Score: 8.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56/339e59996ff193adcf1c438cf05f19e753beb3a7/ecde45cd81dc28f5696c312c5ce5a509962e9ab1/be218a01aadffe33ed4fc73e25276d676ebbd09d/aad605a450611e2a7b7cf9dd5724004d39192bfb/967a5ff8a614d10126b6d46db1ac040948d6cb42/111f8d74a19d85942ecbb3aba78f6f3c88e59391

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89782 (🔒)
GCVE (CVE): GCVE-0-2026-89782
GCVE (VulDB): GCVE-100-405562

Entryinfo

Created: 09/16/2026 11:02
Changes: 09/16/2026 11:02 (60)
Complete: 🔍
Cache ID: 216::103

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