CVE-2026-19730
MediumCVSS 4.2Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
The 'podman quadlet install --replace' command opens the existing Quadlet file without O_TRUNC, which on filesystems without reflink support (e.g., default XFS on RHEL) leads to incomplete overwriting. If the new Quadlet is shorter than the original, old data remains at the end of the file, and the command completes without warning.
Risk Assessment
The risk is that unwanted security options (e.g., AddCapability) or additional volume mounts may remain active after updating a Quadlet, potentially leading to unintended data exposure in containers or privilege escalation.
Recommendation
Immediately update Podman to a patched version and manually inspect Quadlet files after using 'install --replace' for unexpected content. Until patched, avoid this command or use a workaround by deleting the file before installation.
Original NVD description (English source)
The 'podman quadlet install --replace' command opens the existing destination file with O_CREATE|O_WRONLY but omits O_TRUNC. When the initial reflink copy attempt fails (common on non-reflink-capable filesystems including many RHEL default XFS configurations), the fallback in ReflinkOrCopy uses io.Copy which performs a non-truncating write. If the original Quadlet is larger than the new Quadlet, the file is not truncated and content from the original is preserved. The command completes with no warning. There is no risk of information leakage as the user already had access to the Quadlet in order to replace it, and in most cases, this would only lead to invalid Quadlet files. However, security-related options from the end of the old Quadlet could be included in the new Quadlet, and if the truncation resulted in a valid Quadlet file, this could result in undesirable behavior. For example, running podman quadlet install --replace to remove a single line from the end of a Quadlet - including security-sensitive content, like AddCapability - will fail, and the option will continue to be used. Further, with Volume Quadlets, this can include additional mounts which can cause content to be unintentionally exposed into containers. If, later, the image is updated then compromised content might be leaked to an attacker. The vulnerable code paths are in pkg/domain/infra/abi/quadlet.go (lines 338-360, O_CREATE|O_WRONLY without O_TRUNC) and vendor/go.podman.io/storage/pkg/fileutils/reflink_linux.go (lines 12-19, non-truncating io.Copy fallback).