Linux KernelOperating system · Linux
CVE-2026-53076
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 · uneditedIn the Linux kernel, the following vulnerability has been resolved: bpf: Fix OOB in pcpu_init_value An out-of-bounds read occurs when copying element from a BPF_MAP_TYPE_CGROUP_STORAGE map to another pcpu map with the same value_size that is not rounded up to 8 bytes. The issue happens when: 1. A CGROUP_STORAGE map is created with value_size not aligned to 8 bytes (e.g., 4 bytes) 2. A pcpu map is created with the same value_size (e.g., 4 bytes) 3. Update element in 2 with data in 1 pcpu_init_value assumes that all sources are rounded up to 8 bytes, and invokes copy_map_value_long to make a data copy, However, the assumption doesn't stand since there are some cases where the source may not be rounded up to 8 bytes, e.g., CGROUP_STORAGE, skb->data. the verifier verifies exactly the size that the source claims, not the size rounded up to 8 bytes by kernel, an OOB happens when the source has only 4 bytes while the copy size(4) is rounded up to 8.
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 confidenceAn out-of-bounds read vulnerability exists in the Linux kernel's BPF subsystem where pcpu_init_value incorrectly assumes all source maps have value sizes rounded up to 8 bytes. When copying from a BPF_MAP_TYPE_CGROUP_STORAGE map (which uses exact size, e.g., 4 bytes) to a pcpu map with the same non-8-byte-aligned value_size, the copy function rounds the copy size to 8 bytes, causing an OOB read beyond the source buffer's bounds.
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
>= 5.4.78, < 5.5>= 5.9.9, < 5.10>= 5.10.1, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10= 5.10CVSS 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
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 checksWork through these to decide whether this CVE applies to you.
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Verify BPF subsystem is enabledCheck kernel configuration for CONFIG_BPF and CONFIG_BPF_SYSCALL (e.g., grep -E 'CONFIG_BPF' /boot/config-$(uname -r) or check /sys/kernel/bpf)Affected if BPF is not compiled into the kernel, the vulnerability does not apply
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Check for cgroup BPF controller availabilityVerify cgroup BPF functionality is present: ls /sys/fs/cgroup/ and check if bpf progs or maps can be created (e.g., bpftool map show)Affected if cgroup controller is not available, CGROUP_STORAGE maps cannot be created and the vulnerability cannot be triggered
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Identify CGROUP_STORAGE maps with unaligned value sizesList all BPF maps using 'bpftool map show' or 'cat /proc/sys/kernel/bpf_map' and check the 'value_size' field; look for maps of type 17 (CGROUP_STORAGE) where value_size is not a multiple of 8 (e.g., 4, 12, 20)Affected if a CGROUP_STORAGE map exists with value_size not divisible by 8 bytes, and that map is used as a source for pcpu map updates
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Check for pcpu maps receiving updates from CGROUP_STORAGEExamine BPF programs that perform map_update operations from CGROUP_STORAGE to percpu (pcpu) maps; use 'bpftool prog show' and trace map references in program detailsAffected if a pcpu (percpu) map receives updates from a CGROUP_STORAGE map with non-8-byte-aligned value_size, the vulnerability is triggered
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Verify kernel version against upstream fix statusCompare running kernel version (uname -r) against the kernel version containing the fix for this CVE in your distribution's security advisoryAffected if the kernel version predates the CVE fix and conditions in steps 1-4 are met
If the kernel has BPF enabled, CGROUP_STORAGE maps with non-8-byte-aligned value_size exist, and those maps are used as sources for pcpu map updates, the environment is affected by this OOB read vulnerability.
Generated from the published advisory. Verify against your own configuration.
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 · scoped5.55.106.6.141
Apply the upstream kernel patch for this vulnerability which adds proper validation in pcpu_init_value to handle sources that are not rounded up to 8 bytes, ensuring copy operations respect the actual source buffer size.
Linux Kernel 6.12.91 or later (or 6.6.141+ for 6.6 LTS, 5.10+ for 5.10.y, 5.5+ for 5.5.y)
- 1. Identify the currently running Linux kernel version using `uname -r`
- 2. Check if your current kernel version falls within any of the affected ranges: >= 5.4.78 and < 5.5, >= 5.9.9 and < 5.10, >= 5.10.1 and < 6.6.141, or >= 6.7 and < 6.12.91
- 3. If affected, update the kernel package to a fixed version: 6.12.91 or later for the 6.12 stable branch (or 6.6.141+ for the 6.6 LTS branch, 5.10+ for the 5.10 branch, or 5.5+ for the 5.5 branch depending on your distribution's support cycle
- 4. Reboot the system to load the patched kernel
- 5. Verify the new kernel version is running with `uname -r` and confirm it is no longer in the affected version range
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-53076 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-53076 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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