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Linux KernelOperating system · Linux

CVE-2026-53337

MEDIUM · 5.5 CVSS v3.1 Published 2026-07-01
Fix available
A fix is available. Upgrade to 5.10.259 / 5.15.210 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: net: bonding: fix NULL pointer dereference in bond_do_ioctl() In bond_do_ioctl(), slave_dev is obtained via __dev_get_by_name() which can return NULL if the requested interface name does not exist. However, the subsequent slave_dbg() call is placed before the NULL check: slave_dev = __dev_get_by_name(net, ifr->ifr_slave); slave_dbg(bond_dev, slave_dev, "slave_dev=%p:\n", slave_dev); //here if (!slave_dev) return -ENODEV; The slave_dbg() macro expands to netdev_dbg(bond_dev, "(slave %s): " fmt, (slave_dev)->name, ...) which unconditionally dereferences slave_dev->name before the NULL check is performed. This results in a NULL pointer dereference kernel oops when a user calls bonding ioctl (e.g. SIOCBONDENSLAVE, SIOCBONDRELEASE, etc.) with a non-existent slave interface name. This is reachable from userspace via the bonding ioctl interface with CAP_NET_ADMIN capability, making it a potential local denial-of-service vector. Fix by moving the slave_dbg() call after the NULL check.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A NULL pointer dereference vulnerability exists in the Linux kernel's bond_do_ioctl() function where the slave_dbg() macro is called before validating that slave_dev is non-NULL. Since slave_dbg() expands to netdev_dbg which dereferences slave_dev->name, providing a non-existent interface name to bonding ioctls (SIOCBONDENSLAVE, SIOCBONDRELEASE, etc.) causes a kernel oops, resulting in local denial-of-service.

MitigationApply the upstream fix by moving the slave_dbg() call after the NULL check, or backport the patch if running an older kernel version. Restrict CAP_NET_ADMIN capability to trusted users to reduce attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.3, < 5.10.259>= 5.11, < 5.15.210>= 5.16, < 6.1.176>= 6.2, < 6.6.143>= 6.7, < 6.12.94>= 6.13, < 6.18.36>= 6.19, < 7.0.13= 7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version against affected ranges
    Run 'uname -r' or 'cat /proc/version' to obtain the kernel version, then compare against: >= 5.3, < 5.10.259; >= 5.11, < 5.15.210; >= 5.16, < 6.1.176; >= 6.2, < 6.6.143; >= 6.7, < 6.12.94; >= 6.13, < 6.18.36; >= 6.19, < 7.0.13; = 7.1
    Affected if Kernel version falls within any of the listed vulnerable ranges
  2. Verify if bonding module is loaded
    Run 'lsmod | grep bonding' or check /sys/class/net for bond* interfaces
    Affected if Bonding module is loaded or any bond interfaces exist
  3. Check for active bond interfaces with slaves
    Run 'ip link show' or 'cat /proc/net/bonding/bond*' to list configured bond interfaces and their slaves
    Affected if Any bond interface with slave interfaces is configured and active

Environment is affected if the kernel version is within the vulnerable ranges AND bonding with slave interfaces is in use, as the NULL pointer dereference occurs when bond_do_ioctl() processes ioctls referencing slave interfaces.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.10.259 / 5.15.210 / 6.1.176 or later
Fixed in 5.10.2595.15.2106.1.176
Interim mitigation

Apply the upstream fix by moving the slave_dbg() call after the NULL check, or backport the patch if running an older kernel version. Restrict CAP_NET_ADMIN capability to trusted users to reduce attack surface.

Recommended fix High confidence

6.6.143 (or latest stable 6.6.x release)

  1. Identify the currently running kernel version using 'uname -r'
  2. Check if the current version is affected by comparing against the vulnerable ranges: >= 5.3 && < 5.10.259, >= 5.11 && < 5.15.210, >= 5.16 && < 6.1.176, or >= 6.2 && < 6.6.143
  3. If affected, upgrade the Linux kernel to a fixed release: 5.10.259 or later for the 5.10 branch, 5.15.210 or later for the 5.15 branch, 6.1.176 or later for the 6.1 branch, or 6.6.143 or later for the 6.6 branch
  4. For enterprise distributions, apply vendor-provided kernel updates which include this fix
  5. Reboot the system into the updated kernel
  6. Verify the fix is applied by checking the kernel version and confirming the bonding ioctl no longer crashes on non-existent slave interface names
Caveat Minimal risk - this is a bug fix for a NULL pointer dereference; the upgrade introduces no functional changes to bonding behavior beyond fixing the crash

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,190
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53337 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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