CVE-2026-43420
4.7 · MEDIUMOverview
CVE-2026-43420 is a medium-severity vulnerability affecting linux linux_kernel. It was published on May 8, 2026 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix i_nlink underrun during async unlink
During async unlink, we drop the `i_nlink` counter before we receive
the completion (that will eventually update the `i_nlink`) because "we
assume that the unlink will succeed". That is not a bad idea, but it
races against deletions by other clients (or against the completion of
our own unlink) and can lead to an underrun which emits a WARNING like
this one:
WARNING: CPU: 85 PID: 25093 at fs/inode.c:407 drop_nlink+0x50/0x68
Modules linked in:
CPU: 85 UID: 3221252029 PID: 25093 Comm: php-cgi8.1 Not tainted 6.14.11-cm4all1-ampere #655
Hardware name: Supermicro ARS-110M-NR/R12SPD-A, BIOS 1.1b 10/17/2023
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drop_nlink+0x50/0x68
lr : ceph_unlink+0x6c4/0x720
sp : ffff80012173bc90
x29: ffff80012173bc90 x28: ffff086d0a45aaf8 x27: ffff0871d0eb5680
x26: ffff087f2a64a718 x25: 0000020000000180 x24: 0000000
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.7, < 5.10.253 | Affected |
References
Frequently Asked Questions
What is CVE-2026-43420?
CVE-2026-43420 is a medium-severity vulnerability affecting linux linux_kernel. It was published on May 8, 2026 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
How severe is CVE-2026-43420?
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-43420?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-43420?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-43420 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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