Linux: Out-of-bounds Read
CVE-2026-53303 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d3ff0c121bbaef026df6248ab7ef6f0b068b0647, cea15f66b7b68b2c50943a6660e0692c6635e4eb, 4b3a1bf4c2ffd4c9595d900ead78c9035894a025 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 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d3ff0c121bbaef026df6248ab7ef6f0b068b0647 or cea15f66b7b68b2c50943a6660e0692c6635e4eb or 4b3a1bf4c2ffd4c9595d900ead78c9035894a025 or d0e877810baf613b018fd9747440b9d4d9db1428, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.175 or 6.6.141 or 6.12.91 or 6.18.33, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, d3ff0c121bbaef026df6248ab7ef6f0b068b0647; b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, cea15f66b7b68b2c50943a6660e0692c6635e4eb; b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, 4b3a1bf4c2ffd4c9595d900ead78c9035894a025; b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, d0e877810baf613b018fd9747440b9d4d9db1428; b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, ea3ab43a1f3cf2c7cecd75c8be1ee99a5e94a92e; b6a06cbbb5f7fd03589cff9178314af04c568826 up to, but not including, 5909bedbed38c558bee7cb6758ceedf9bc3a9194; 4.17 | d3ff0c121bbaef026df6248ab7ef6f0b068b0647, cea15f66b7b68b2c50943a6660e0692c6635e4eb, 4b3a1bf4c2ffd4c9595d900ead78c9035894a025, d0e877810baf613b018fd9747440b9d4d9db1428, ea3ab43a1f3cf2c7cecd75c8be1ee99a5e94a92e, 5909bedbed38c558bee7cb6758ceedf9bc3a9194 |
| Linux | Linux Kernel | 4.17 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, 7.0.10 | 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10 |
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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: f2fs: protect extension_list reading with sb_lock in f2fs_sbi_show() In f2fs_sbi_show(), the extension_list, extension_count and hot_ext_count are read without holding sbi->sb_lock. If a concurrent sysfs store modifies the extension list via f2fs_update_extension_list(), the show path may read inconsistent count and array contents, potentially leading to out-of-bounds access or displaying stale data. Fix this by holding sb_lock around the entire extension list read and format operation.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/4b3a1bf4c2ffd4c9595d900ead78c9035894a025
- git.kernel.org/stable/c/5909bedbed38c558bee7cb6758ceedf9bc3a9194
- git.kernel.org/stable/c/cea15f66b7b68b2c50943a6660e0692c6635e4eb
- git.kernel.org/stable/c/d0e877810baf613b018fd9747440b9d4d9db1428
- git.kernel.org/stable/c/d3ff0c121bbaef026df6248ab7ef6f0b068b0647
- git.kernel.org/stable/c/ea3ab43a1f3cf2c7cecd75c8be1ee99a5e94a92e
Recent Out-of-bounds Read vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
- 8.4 High severity
- 9.1 Critical severity
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