CVE-2026-64324
In the Linux kernel, the following vulnerability has been resolved: udf: validate free block extents against the partition length udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: udf: validate free block extents against the partition length udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.16% probability · 5th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-129, CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1fPatch
- https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3Patch
- https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168Patch
- https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240Patch
- https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70cPatch
- https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2bPatch
- https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99ePatch
- https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.