# CVE-2020-10761: qemu: An assertion failure issue was found in the Network Block Device(NBD) Server in all QEMU versions before QEMU 5.0.1 CVE-2020-10761 is fixed in 21 products on 1 platform, first by qemu 1:4.2-3ubuntu6.4, released August 11, 2020. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2020-10761 - Priority: Routine - CVSS: n/a (Medium) - EPSS: 0.0180 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 9, 2020 ## Description An assertion failure issue was found in the Network Block Device(NBD) Server in all QEMU versions before QEMU 5.0.1. This flaw occurs when an nbd-client sends a spec-compliant request that is near the boundary of maximum permitted request length. A remote nbd-client could use this flaw to crash the qemu-nbd server resulting in a denial of service. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | qemu Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-block-extra Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-block-extra 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-block-extra-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-guest-agent Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-guest-agent 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-guest-agent-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-kvm Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-kvm 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-kvm-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-arm Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-arm 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-arm-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-common Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-common 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-common-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-data Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-data 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-data-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-gui Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-gui 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-gui-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-mips Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-mips 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-mips-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-misc Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-misc 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-misc-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-ppc Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-ppc 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-ppc-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-s390x Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-s390x 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-s390x-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-sparc Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-sparc 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-sparc-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-x86 Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-x86 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-x86-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-x86-microvm Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-x86-microvm 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-x86-microvm-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-system-x86-xen Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-system-x86-xen 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-system-x86-xen-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-user Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-user 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-user-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-user-binfmt Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-user-binfmt 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-user-binfmt-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-user-static Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-user-static 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-user-static-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | | Linux | qemu-utils Ubuntu 20.04 LTS (focal) | 1:4.2-3ubuntu6.4 | [qemu-utils 1:4.2-3ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-qemu-utils-1-4.2-3ubuntu6.4.md) | Aug 11, 2020 | --- Data as of 2026-11-09T07:25:28Z UTC. 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