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Linux KernelOperating system · Linux

CVE-2026-53110

HIGH · 7.8 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 6.6.141 / 6.12.91 or later.
See remediation →
80/100
Remediation priority · High
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: s390/bpf: Zero-extend bpf prog return values and kfunc arguments s390x ABI requires callers to zero-extend unsigned arguments and sign-extend signed arguments, and callees to zero-extend unsigned return values and sign-extend signed return values. s390 BPF JIT currently implements only sign extension. Fix this omission and implement zero extension too.

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 s390x BPF JIT compiler incorrectly handles unsigned value returns and kfunc arguments by only implementing sign extension instead of zero extension as required by the s390x ABI. When BPF programs return unsigned 64-bit values, the upper bits are not properly zeroed, potentially causing incorrect behavior in downstream code expecting proper zero-extension.

MitigationThis kernel-level vulnerability requires patching the s390 BPF JIT to add zero-extension logic for unsigned return values and kfunc arguments. Organizations running s390x systems should apply kernel updates containing the fix.

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:>= 6.3, < 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
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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. Confirm system architecture is s390x
    Run 'uname -m' or check /proc/cpuinfo for the 'machine' field. Look for 's390x' in the output.
    Affected if The architecture is s390x (other architectures are not affected by this specific ABI violation)
  2. Verify BPF JIT compiler is enabled
    Check the kernel configuration or runtime status: look for CONFIG_BPF_JIT=y in /boot/config-$(uname -r), or check /proc/sys/net/core/bpf_jit_enable (value should be 1 or 2).
    Affected if BPF JIT is enabled on s390x - the flaw only applies when the JIT compiler processes BPF programs
  3. Identify BPF programs using unsigned return values or arguments
    Review BPF program source code for functions returning 'unsigned int', 'unsigned long', or similar unsigned types, or taking unsigned arguments. Use 'bpftool prog dump' to inspect loaded programs.
    Affected if BPF programs with unsigned return types or unsigned arguments are loaded and executed via JIT-compiled path
  4. Check kernel version against patch availability
    Run 'uname -r' to get kernel version. Compare against the version where the fix was merged. Without the fix, unsigned values may be incorrectly sign-extended.
    Affected if Kernel is older than the version containing the s390x BPF JIT zero-extension fix

A system is affected if it runs on s390x architecture with BPF JIT enabled and executes BPF programs that use unsigned return values or unsigned arguments, on a kernel lacking the zero-extension fix.

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.

From vendor data
Upgrade available Upgrade to 6.6.141 / 6.12.91 / 6.18.33 or later
Fixed in 6.6.1416.12.916.18.33
Vendor patch git.kernel.org →
Interim mitigation

This kernel-level vulnerability requires patching the s390 BPF JIT to add zero-extension logic for unsigned return values and kfunc arguments. Organizations running s390x systems should apply kernel updates containing the fix.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

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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-2026-53110 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