CVE-2026-53130 | fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START

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.

Published: 2026-06-24 Last update: 2026-06-28 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2026-53130 is rated Low Risk (32.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.13%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-53130

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-28 0.18% 0.13% -0.05%
2 2026-06-25 0.18%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-53130

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Weakness enumeration for CVE-2026-53130

GitHub Security Advisory for CVE-2026-53130

GHSA-2j9j-p8f4-hwp3 · Severity: high — In the Linux kernel, the following vulnerability has been resolved: fs/omfs: reject...

OS Trackers for CVE-2026-53130

vendor priority summary link
debian not yet assigned CVE-2026-53130 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-53130
redhat https://access.redhat.com/security/cve/CVE-2026-53130
ubuntu high CVE-2026-53130 high priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1045, ignored 172, needed 133, released 87, pending 11, needs-triage 1. https://ubuntu.com/security/CVE-2026-53130

Affected software / configurations for CVE-2026-53130

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.27, < 5.10.258 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 5.15.209 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 6.1.175 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 6.6.141 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 6.12.91 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 6.18.33 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 7.0.10 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.27, < 7.1 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2026-53130

cvelogic Threat Intelligence