# CVE-2026-53130: linux: In the Linux kernel, the following vulnerability has been resolved:  fs/omfs: reject s_sys_blocksize smaller than OMF...

CVE-2026-53130 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53130, released June 25, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-53130
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0019
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 24, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START  omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE), but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).  Later, omfs_make_empty() uses      sbi->s_sys_blocksize - OMFS_DIR_START  as the length argument to memset().  Since s_sys_blocksize is u32, a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes an unsigned underflow there, wrapping to a value near 2^32.  That drives a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel memory far beyond the backing block buffer.  Add the corresponding lower-bound check alongside the existing upper-bound check in omfs_fill_super(), so that malformed images are rejected during superblock validation before any filesystem data is processed.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.176-1 | [DEBIAN-CVE-2026-53130](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53130.md) | Jun 25, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-53130](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53130.md) | Jun 25, 2026 |
| Linux | linux Debian 14 | 7.0.10-1 | [DEBIAN-CVE-2026-53130](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53130.md) | Jun 25, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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