CyberSecBulletin
CVE-2026-53130NVD status: Analyzed

Linux: Integer Underflow (Wrap or Wraparound)

Published Updated By the CyberSecBulletin desk

CVE-2026-53130 is a high-severity integer underflow (wrap or wraparound) vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions fbc72f5c645155dc2ed3573243ed20f9913e3a54, 5822a05a841a10794ad818620dd2af490b0705d3, 754ff1bea3819a90c6f33cccfc1a299ef7609f07 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to fbc72f5c645155dc2ed3573243ed20f9913e3a54 or 5822a05a841a10794ad818620dd2af490b0705d3 or 754ff1bea3819a90c6f33cccfc1a299ef7609f07 or 131ea3e57fc22936ed0e2c8330f2e36106172f51, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, whichever matches your release line, or a later version.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, fbc72f5c645155dc2ed3573243ed20f9913e3a54; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 5822a05a841a10794ad818620dd2af490b0705d3; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 754ff1bea3819a90c6f33cccfc1a299ef7609f07; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 131ea3e57fc22936ed0e2c8330f2e36106172f51; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 79f84af38c9fef9deb0e02c79eb969b5541c2644; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 6561afc38398e3518a29c5eebb975c30468f98a6; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 817f16ed62bc58a168417bfb5e859c2a370bab03; a3ab7155ea21aadc8a4d5687e91b3d876973185e up to, but not including, 0621c385fda1376e967f37ccd534c26c3e511d14; and 1 more rangesfbc72f5c645155dc2ed3573243ed20f9913e3a54, 5822a05a841a10794ad818620dd2af490b0705d3, 754ff1bea3819a90c6f33cccfc1a299ef7609f07, 131ea3e57fc22936ed0e2c8330f2e36106172f51, 79f84af38c9fef9deb0e02c79eb969b5541c2644, 6561afc38398e3518a29c5eebb975c30468f98a6
LinuxLinux Kernel2.6.27 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.105.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA.

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

More Integer Underflow (Wrap or Wraparound) vulnerabilities (CWE-191)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Integer Underflow (Wrap or Wraparound) vulnerabilities

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