CVE-2026-43336 lib/crypto: chacha: Zeroize permuted_state before it leaves scope

What is CVE-2026-43336?

CVE-2026-43336 is a high-severity vulnerability in Linux kernel, published on 8 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:

lib/crypto: chacha: Zeroize permuted_state before it leaves scope

Since the ChaCha permutation is invertible, the local variable 'permuted_state' is sufficient to compute the original 'state', and thus the key, even after the permutation has been done.

While the kernel is quite inconsistent about zeroizing secrets on the stack (and some prominent userspace crypto libraries don't bother at all since it's not guaranteed to work anyway), the kernel does try to do it as a best practice, especially in cases involving the RNG.

Thus, explicitly zeroize 'permuted_state' before it goes out of scope.

Which versions are affected by CVE-2026-43336?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43336?

Apply the vendor's patch.

Is CVE-2026-43336 being exploited?

There is no known exploitation of CVE-2026-43336 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-2026-43336, DEBIAN-CVE-2026-43336, GHSA-cw2x-g67m-8387, ROOT-OS-DEBIAN-11-CVE-2026-43336, ROOT-OS-UBUNTU-2204-CVE-2026-43336, ROOT-OS-UBUNTU-2404-CVE-2026-43336 and 1 more.