CVE-2026-23383: Linux kernel · bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1061.64~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1061.64~22.04.1, 6.8.0-1063.71~22.04.1, 6.8.0-1062.69~22.04.1 +30
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been released in updated Linux kernel versions including those distributed by Ubuntu. Users should update their Linux kernel to version 6.8.0 or later (or the corresponding patched package versions) and reboot the system to apply the fix. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. No additional mitigations are specified beyond applying the official patch.
Description
A high-severity vulnerability (CVE-2026-23383) in the Linux kernel's BPF JIT allocator on arm64 architecture was fixed by enforcing 8-byte alignment for the JIT buffer. Previously, the buffer was only 4-byte aligned, which could cause atomic tearing during concurrent updates of a 64-bit target field, potentially leading to corrupted jumps in JIT-compiled code. This issue affects multiple Linux kernel versions prior to 6.8.0 and related builds. A patch is available and included in recent Linux kernel updates. Users should apply the update and reboot to mitigate the risk.
References
- ubuntu.com/security/CVE-2026-23383 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23383 (opens in a new tab)
- git.kernel.org/linus/ef06fd16d48704eac868441d98d4ef083d8f3d07 (opens in a new tab)
- git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1de (opens in a new tab)
- git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6 (opens in a new tab)
- git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dc (opens in a new tab)
- git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8607-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8608-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8609-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8619-1 (opens in a new tab)