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Linux KernelOperating system · Linux

CVE-2026-53095

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 6.18.33 / 7.0.10 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available 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 abuse of kprobe_write_ctx via freplace uprobe programs are allowed to modify struct pt_regs. Since the actual program type of uprobe is KPROBE, it can be abused to modify struct pt_regs via kprobe+freplace when the kprobe attaches to kernel functions. For example, SEC("?kprobe") int kprobe(struct pt_regs *regs) { return 0; } SEC("?freplace") int freplace_kprobe(struct pt_regs *regs) { regs->di = 0; return 0; } freplace_kprobe prog will attach to kprobe prog. kprobe prog will attach to a kernel function. Without this patch, when the kernel function runs, its first arg will always be set as 0 via the freplace_kprobe prog. To fix the abuse of kprobe_write_ctx=true via kprobe+freplace, disallow attaching freplace programs on kprobe programs with different kprobe_write_ctx values.

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

The Linux kernel BPF subsystem allows freplace (function replacement) programs to attach to kprobe programs. A vulnerability exists where freplace programs can bypass kprobe_write_ctx restrictions - if a kprobe has kprobe_write_ctx=true, a freplace program attached to it can also modify struct pt_regs even when it shouldn't have that permission. This allows unauthorized modification of kernel function arguments.

MitigationApply the kernel patch that enforces matching kprobe_write_ctx values between kprobe and freplace programs during attachment, preventing the bypass. Ensure Linux kernel is updated to the patched version.

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:>= 6.18, < 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 kernel version
    Run 'uname -r' or read /proc/version and compare the version numbers to the affected ranges: >= 6.18, < 6.18.33 and >= 6.19, < 7.0.10
    Affected if The installed kernel version falls within any of the affected ranges
  2. Identify loaded BPF kprobe programs
    Use 'bpftool prog list' or 'cat /sys/kernel/debug/tracing/available_filter_functions' to enumerate kprobe-type BPF programs currently loaded
    Affected if Any kprobe-type BPF programs are attached to the kernel
  3. Check for freplace (function replacement) BPF programs
    Use 'bpftool prog list' and examine program types, looking for freplace programs or programs with type 'freplace' that are attached to kprobe attachments
    Affected if Any freplace programs are attached to kprobe program attachments
  4. Verify kprobe_write_ctx flag configuration
    Examine the kprobe_write_ctx attribute of any kprobe programs using 'bpftool prog show' or by inspecting the BPF program metadata
    Affected if A kprobe program with kprobe_write_ctx=0 has a freplace program attached with kprobe_write_ctx=1, or vice versa (mismatched values)
  5. Check for uprobe programs with KPROBE type
    Use 'bpftool prog list' to identify uprobe programs that have KPROBE type and are involved in freplace attachments
    Affected if Any uprobe programs with KPROBE type are attached via freplace to kprobe programs enabling argument modification

You are affected if your kernel version is between 6.18 and 6.18.32 (inclusive) or between 6.19 and 7.0.9 (inclusive), AND you have BPF kprobe programs with attached freplace programs that have mismatched kprobe_write_ctx values.

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 6.18.33 / 7.0.10 or later
Fixed in 6.18.337.0.10
Vendor patch git.kernel.org →
Interim mitigation

Apply the kernel patch that enforces matching kprobe_write_ctx values between kprobe and freplace programs during attachment, preventing the bypass. Ensure Linux kernel is updated to the patched version.

Recommended fix High confidence

Linux Kernel 6.18.33 or 7.0.10 (or later stable release)

  1. Identify current kernel version using `uname -r`
  2. If running kernel >= 6.18 and < 6.18.33, upgrade to kernel 6.18.33 or later
  3. If running kernel >= 6.19 and < 7.0.10, upgrade to kernel 7.0.10 or later
  4. After upgrade, reboot the system to load the fixed kernel
  5. Verify the fix is applied by checking the kernel version matches a fixed release
Caveat Major kernel upgrades may require rebuilding out-of-tree kernel modules or driver packages; ensure compatible software 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
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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Scan for this in your stack

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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-2026-53095 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data