Linux KernelOperating system · Linux
CVE-2026-23383
A fix is available.
Upgrade to 6.12.77 / 6.18.17 or later.
See remediation →
80/100
Remediation priority · High
Zero-click
Patch available
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, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing struct bpf_plt contains a u64 target field. Currently, the BPF JIT allocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT buffer. Because the base address of the JIT buffer can be 4-byte aligned (e.g., ending in 0x4 or 0xc), the relative padding logic in build_plt() fails to ensure that target lands on an 8-byte boundary. This leads to two issues: 1. UBSAN reports misaligned-access warnings when dereferencing the structure. 2. More critically, target is updated concurrently via WRITE_ONCE() in bpf_arch_text_poke() while the JIT'd code executes ldr. On arm64, 64-bit loads/stores are only guaranteed to be single-copy atomic if they are 64-bit aligned. A misaligned target risks a torn read, causing the JIT to jump to a corrupted address. Fix this by increasing the allocation alignment requirement to 8 bytes (sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of the JIT buffer to an 8-byte boundary, allowing the relative padding math in build_plt() to correctly align the target field.
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 analysisA detailed technical summary for this CVE is being prepared.
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:
>= 6.0.1, < 6.12.77>= 6.13, < 6.18.17>= 6.19, < 6.19.7= 6.0= 7.0CVSS 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
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 6.12.77 / 6.18.17 / 6.19.7 or later
Fixed in
6.12.776.18.176.19.7
Vendor patch
git.kernel.org →
Recommended fix
High confidence
6.12.77 (or 6.18.17, 6.19.7, or later stable kernel)
- 1. Identify the currently running Linux kernel version using `uname -r`
- 2. Determine which kernel branch your system is based on (e.g., 6.12.y, 6.18.y, 6.19.y, or a distribution-specific kernel)
- 3. Upgrade the Linux kernel to a version that includes the fix: for 6.12.x upgrade to >= 6.12.77, for 6.13-6.18.x upgrade to >= 6.18.17, for 6.19.x upgrade to >= 6.19.7
- 4. On Debian/Ubuntu-based systems: run `sudo apt-get update && sudo apt-get dist-upgrade` or install a newer kernel package
- 5. On RHEL/CentOS-based systems: run `sudo yum update kernel` or `sudo dnf update kernel`
- 6. On Arch Linux: run `sudo pacman -Syu linux`
- 7. For custom/compiled kernels: apply the commit 519b1ad91de5bf7a496f2b858e9212db6328e1de which changes the alignment from 4 to 8 bytes in the bpf_jit_binary_pack_alloc() function
- 8. Reboot the system to load the updated kernel
Caveat Kernel upgrades may require system reboot and could introduce compatibility issues with custom modules or specific hardware drivers; ensure backups and test in non-production environments first
Generated from the published advisory — verify against the referenced sources before acting.
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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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-23383 in production — separate from our analysis above.
Know something about CVE-2026-23383?
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
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What belongs here
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