CVE-2026-43493 crypto: pcrypt - Fix handling of MAY_BACKLOG requests

What is CVE-2026-43493?

CVE-2026-43493 is a critical denial of service vulnerability in Linux kernel, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

crypto: pcrypt - Fix handling of MAY_BACKLOG requests

MAY_BACKLOG requests can return EBUSY. Handle them by checking for that value and filtering out EINPROGRESS notifications.

Weakness: CWE-390

Which versions are affected by CVE-2026-43493?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43493?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-43493 being exploited?

There is no known exploitation of CVE-2026-43493 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-43493, DEBIAN-CVE-2026-43493, GHSA-v9g7-8cgp-9v29, ROOT-OS-DEBIAN-11-CVE-2026-43493, ROOT-OS-DEBIAN-12-CVE-2026-43493, ROOT-OS-UBUNTU-2204-CVE-2026-43493 and 2 more.