Vulnerability · Published Jul 29, 2026 · Assigned by Linux

CVE-2026-64558s390/pkey: Check length in pkey_pckmo handler implementation

High 7.8

In plain English

A high-severity heap buffer overflow in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 98.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Check length in pkey_pckmo handler implementation Explicitly check the length of the target buffer in the pkey_pckmo implementation of the key_to_protkey() handler function. The handler function fails, if the generated output data exceeds the length of the provided target buffer.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.100-1DEBIAN-CVE-2026-64558
Debian:14linux7.1.5-1DEBIAN-CVE-2026-64558
Debian:12linux-6.126.12.100-1~deb12u1DEBIAN-CVE-2026-64558
Ubuntu:26.04:LTSlinux7.0.0-38.38UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux7.0.0-38.38USN-8887-1
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-aws7.0.0-1014.14USN-8887-1
Ubuntu:26.04:LTSlinux-aws7.0.0-1014.14UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-aws-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-aws-7.07.0.0-1014.14~24.04.1USN-8887-2
Ubuntu:26.04:LTSlinux-azure7.0.0-1017.17UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-azure7.0.0-1017.17USN-8888-1
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1017.17~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1017.17~24.04.1USN-8888-2
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1016.16UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1016.16USN-8888-1
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1016.16~24.04.1USN-8888-2
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-gcp7.0.0-1014.14UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-gcp7.0.0-1014.14USN-8887-1
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1014.14~24.04.1USN-8887-3
Ubuntu:26.04:LTSlinux-gke7.0.0-1008.9USN-8887-1
Ubuntu:26.04:LTSlinux-gke7.0.0-1008.9UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-38.38~24.04.4UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-38.38~24.04.4USN-8887-3
Ubuntu:26.04:LTSlinux-ibm7.0.0-1015.15UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-ibm7.0.0-1015.15USN-8887-1
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1024.25~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1024.25~24.04.1USN-9003-1
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2022.23USN-9003-1
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2022.23UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1015.15UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1015.15USN-8889-1
Ubuntu:26.04:LTSlinux-oracle7.0.0-1013.13UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-oracle7.0.0-1013.13USN-8887-1
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1013.13~24.04.1USN-8887-3
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-realtime7.0.0-38.38.1USN-8887-1
Ubuntu:26.04:LTSlinux-realtime7.0.0-38.38.1UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64558
Ubuntu:26.04:LTSlinux-riscv7.0.0-38.38.1UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-64558
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-38.38.1~24.04.1UBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-64558
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-64558

Affected products (as reported)

VendorProductVersions
Linux Linux 8fcc231ce3bea12b78bb94b280cdc03cff342435 – before 02028a24e26d85262ab9c8fc4344e1f3503007fc8fcc231ce3bea12b78bb94b280cdc03cff342435 – before 433e5e70cdc1edf382d28d08a885b22e2b98b7da8fcc231ce3bea12b78bb94b280cdc03cff342435 – before 614aa0491c7a190556c2345dddee0b6f5ed909898fcc231ce3bea12b78bb94b280cdc03cff342435 – before 1ac287e2af9a9112fe271427ef45eceb26bce8b4
Linux Linux 6.12

Weakness: CWE-122 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References