CyberSecBulletin
CVE-2026-52927NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-52927 is a high-severity out-of-bounds read 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 attacker with a low-privileged account, without any action from a user. The record lists versions d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00, 21af4c030567d2e6c89bb927bc18b51fba52a400, dad9ebf8107955bb54bd3f9cf22591b6ff37bac1 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 0.12% 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 d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00 or 21af4c030567d2e6c89bb927bc18b51fba52a400 or dad9ebf8107955bb54bd3f9cf22591b6ff37bac1 or a27cb7325a6c69970041c7f8541fafed5a1ea3ec, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, 21af4c030567d2e6c89bb927bc18b51fba52a400; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, dad9ebf8107955bb54bd3f9cf22591b6ff37bac1; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, a27cb7325a6c69970041c7f8541fafed5a1ea3ec; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, 7ad0e463fc7eafae2141cc38054264636f8b3e94; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, bf8e8eac7ede51dc318e06acef5a896dcbba7595; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, fcc4c043d137e7f1de4673dba1f3116e45377c67; 81e675c227ec60a0bdcbb547dc530ebee23ff931 up to, but not including, f438d1786d657d57790c5d138d6db3fc9fdac392; and 1 more rangesd7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00, 21af4c030567d2e6c89bb927bc18b51fba52a400, dad9ebf8107955bb54bd3f9cf22591b6ff37bac1, a27cb7325a6c69970041c7f8541fafed5a1ea3ec, 7ad0e463fc7eafae2141cc38054264636f8b3e94, bf8e8eac7ede51dc318e06acef5a896dcbba7595
LinuxLinux Kernel2.6.34 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35

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
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:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ebtables: fix OOB read in compat_mtw_from_user Luxiao Xu says: The function compat_mtw_from_user() converts ebtables extensions from 32-bit user structures to kernel native structures. However, it lacks proper validation of the user-supplied match_size/target_size. When certain extensions are processed, the kernel-side translation logic may perform memory accesses based on the extension's expected size. If the user provides a size smaller than what the extension requires, it results in an out-of-bounds read as reported by KASAN. This fix introduces a check to ensure match_size is at least as large as the extension's required compatsize. This covers matches, watchers, and targets, while maintaining compatibility with standard targets. AFAIU this is relevant for matches that need to go though match->compat_from_user() call. Those that use plain memcpy with the user-provided size are ok because the caller checks that size vs the start of the next rule entry offset (which itself is checked vs. total size copied from userspace). The ->compat_from_user() callbacks assume they can read compatsize bytes, so they need this extra check. Based on an earlier patch from Luxiao Xu.

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.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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