Answer in brief
CVE-2025-40307 records a High severity (CVSS 7.8) vulnerability in exfat: validate cluster allocation bits of the allocation bitmap. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 5.7 | Not reported |
| Linux/Linuxgeneric | >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <87f827d53bd0688597bda63ae95908e2ad39bac0 || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <67ce8034dc0278ddd88cad93d4218a945180dddd || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <6bc58b4c53795ab5fe00648344aa7d9d61175f90 || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <79c1587b6cda74deb0c86fc7ba194b92958c793c | 87f827d53bd0688597bda63ae95908e2ad39bac0, 67ce8034dc0278ddd88cad93d4218a945180dddd, 6bc58b4c53795ab5fe00648344aa7d9d61175f90, 13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf, 79c1587b6cda74deb0c86fc7ba194b92958c793c |
| Linux/Linuxgeneric | >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <67ce8034dc0278ddd88cad93d4218a945180dddd || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <6bc58b4c53795ab5fe00648344aa7d9d61175f90 || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf || >=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <79c1587b6cda74deb0c86fc7ba194b92958c793c | 67ce8034dc0278ddd88cad93d4218a945180dddd, 6bc58b4c53795ab5fe00648344aa7d9d61175f90, 13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf, 79c1587b6cda74deb0c86fc7ba194b92958c793c |
Published upstream
Dec 8, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 3, 2026
In the Linux kernel, the following vulnerability has been resolved: exfat: validate cluster allocation bits of the allocation bitmap syzbot created an exfat image with cluster bits not set for the allocation bitmap. exfat-fs reads and uses the allocation bitmap without checking this. The problem is that if the start cluster of the allocation bitmap is 6, cluster 6 can be allocated when creating a directory with mkdir. exfat zeros out this cluster in exfat_mkdir, which can delete existing entries. This can reallocate the allocated entries. In addition, the allocation bitmap is also zeroed out, so cluster 6 can be reallocated. This patch adds exfat_test_bitmap_range to validate that clusters used for the allocation bitmap are correctly marked as in-use.
Quoted source text, attributed separately from HOL analysis.