Ubuntu USN · USN-8248-2

NASM regression

Published: Fri, 08 May 2026 14:22

CVE-2021-33452CVE-2021-33450

Summary

USN-8248-1 introduced a regression in NASM

Details

USN-8248-1 fixed vulnerabilities in NASM. Unfortunately the update introduced a regression which could cause NASM to crash. This update fixes the problem by reverting the fix for CVE-2021-33450 and CVE-2021-33452 in Ubuntu 24.04 LTS. We apologize for the inconvenience. Original advisory details: Daisy Chen discovered that NASM was vulnerable to a heap buffer overflow when handling certain input. An attacker could possibly use this issue to cause NASM to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2023-31722) It was discovered that NASM incorrectly handled memory allocation. An attacker could possibly use this issue to cause NASM to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 24.04 LTS. (CVE-2021-33452, CVE-2021-33450)

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu noble

nasm→2.16.01-1ubuntu0.1~esm2apt_upgrade_esm
Fixed at 2.16.01-1ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y nasm=2.16.01-1ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
nasm→2.16.01-1ubuntu0.1~esm2apt_upgrade_esm
Fixed at 2.16.01-1ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y nasm=2.16.01-1ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Are YOU affected by USN-8248-2?

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References

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