udf: validate free block extents against the partition length
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-129 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.10.224 to before 5.10.261; 5.15.165 to before 5.15.212; 6.1.105 to before 6.1.178; 6.6.46 to before 6.6.145; 4.19.320 to before 4.20; 5.4.282 to before 5.5; 6.10.5 to before 6.11 | 5.10.261, 5.15.212, 6.1.178, 6.6.145, 4.20, 5.5, 6.11 | Patch available | CNA |
| Linux | Linux | 6.11 and later | 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 5.10.224 to before 5.10.261; 5.15.165 to before 5.15.212; 6.1.105 to before 6.1.178; 6.6.46 to before 6.6.145; 4.19.320 to before 4.20; 5.4.282 to before 5.5; 6.10.5 to before 6.11 Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 4.20, 5.5, 6.11 Patch available CNA
- Linux VendorLinux Affected 6.11 and later Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.19.320 to before 4.20; 5.4.282 to before 5.5; 5.10.224 to before 5.10.261; 5.15.165 to before 5.15.212; 6.1.105 to before 6.1.178; 6.6.46 to before 6.6.145; 6.10.5 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.19.320 to before 4.20; 5.4.282 to before 5.5; 5.10.224 to before 5.10.261; 5.15.165 to before 5.15.212; 6.1.105 to before 6.1.178; 6.6.46 to before 6.6.145; 6.10.5 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 4.20, 5.5, 6.11
- Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64324
- 2026-10-03 Alias added: GHSA-mpf7-xmx2-frhw
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
References
Patch 8
- https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76
- https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c
- https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f
- https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e
- https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240
- https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3
- https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b
- https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-64324 · CVE Program
- CVE-2026-64324 · NVD
- FIRST EPSS
- GHSA-mpf7-xmx2-frhw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64324 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences