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Linux KernelOperating system · Linux

CVE-2026-53032

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 6.5 / 6.6.141 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click 8 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: bpf: Fix NULL deref in map_kptr_match_type for scalar regs Commit ab6c637ad027 ("bpf: Fix a bpf_kptr_xchg() issue with local kptr") refactored map_kptr_match_type() to branch on btf_is_kernel() before checking base_type(). A scalar register stored into a kptr slot has no btf, so the btf_is_kernel(reg->btf) call dereferences NULL. Move the base_type() != PTR_TO_BTF_ID guard before any reg->btf access.

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

NULL pointer dereference in Linux kernel BPF subsystem's map_kptr_match_type() function. When a scalar register (which lacks BTF metadata) is stored into a kptr slot, the code calls btf_is_kernel(reg->btf) without first checking if reg->btf exists, causing a NULL dereference. The fix moves the base_type() != PTR_TO_BTF_ID guard before any reg->btf access.

MitigationApply the kernel patch that repositions the base_type() check to guard against NULL reg->btf access. Update to a kernel version containing the fix for commit ab6c637ad027.

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:>= 6.4.16, < 6.5>= 6.5.3, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10

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 the running kernel version
    Run `uname -r` or `cat /proc/version` to obtain the kernel version
    Affected if The version falls within any of these ranges: >= 6.4.16 and < 6.5; >= 6.5.3 and < 6.6.141; >= 6.7 and < 6.12.91; >= 6.13 and < 6.18.33; >= 6.19 and < 7.0.10
  2. Verify BPF subsystem is available
    Run `ls /sys/kernel/debug/tracing/events/bpf/ 2>/dev/null` or check if `CONFIG_BPF` appears in `/boot/config-$(uname -r)` or `/proc/config.gz` if available
    Affected if The BPF subsystem is compiled into the kernel (the vulnerability exists in the BPF code path)
  3. Identify if BPF maps with kptr type are in use
    Use `bpftool map show` or `cat /proc/sys/kernel/bpf_stats` to enumerate BPF maps; look for maps created with kptr (kernel pointer) type references using `bpftool map dump <id>`
    Affected if Any BPF map is configured with kptr type fields that could receive a scalar register value, triggering the flawed code path in map_kptr_match_type()

You are affected if your kernel version is within the affected ranges AND BPF with kptr map types is in use, as the NULL dereference occurs when storing a scalar register into a kptr slot.

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 6.5 / 6.6.141 / 6.12.91 or later
Fixed in 6.56.6.1416.12.91
Interim mitigation

Apply the kernel patch that repositions the base_type() check to guard against NULL reg->btf access. Update to a kernel version containing the fix for commit ab6c637ad027.

Recommended fix High confidence

Upgrade to Linux kernel 6.5 or later (if using 6.4.x), 6.6.141 or later (if using 6.5.x-6.6.x), 6.12.91 or later (if using 6.7.x-6.12.x), or 6.18.33 or later (if using 6.13.x-6.18.x)

  1. Identify the current Linux kernel version using `uname -r`
  2. Determine which affected version range your kernel falls into based on the version numbers
  3. Upgrade the Linux kernel to one of the fixed versions: 6.5 or later, 6.6.141 or later, 6.12.91 or later, or 6.18.33 or later
  4. For distribution-specific systems, use the appropriate package manager to install the updated kernel (e.g., `apt-get update && apt-get install linux-image-<version>` for Debian/Ubuntu, or `yum update kernel` for RHEL/CentOS)
  5. Reboot the system to load the updated kernel
  6. Verify the new kernel version is running using `uname -r`
Caveat Kernel upgrades may require rebooting the system and could affect third-party kernel modules; ensure compatibility of custom drivers or modules before upgrading

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
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 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-2026-53032 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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