CVE-2026-19730: Incomplete Cleanup in Red Hat Red Hat Enterprise Linux 10
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).
AI Analysis
Technical Summary
The 'podman quadlet install --replace' command opens the destination file with O_CREATE|O_WRONLY but omits O_TRUNC, so when the reflink copy fallback uses io.Copy, it performs a non-truncating write. If the original Quadlet file is larger than the new one, leftover content from the original remains, potentially including security-sensitive options like AddCapability or volume mounts. This can cause Podman to fail to enforce configuration changes intended by the administrator. The vulnerable code is in pkg/domain/infra/abi/quadlet.go (lines 338-360) and vendor/go.podman.io/storage/pkg/fileutils/reflink_linux.go (lines 12-19).
Potential Impact
The vulnerability does not allow information leakage or privilege escalation beyond the user's existing permissions. Instead, it causes Podman to fail to remove or update certain security-related configuration options in Quadlet files, potentially leading to unintended container behavior such as retention of capabilities or volume mounts. This could indirectly lead to exposure of host content into containers or compromised container images leaking content later. The overall impact is limited to configuration enforcement failure with moderate confidentiality, integrity, and availability impacts.
Mitigation Recommendations
Patches addressing this issue are available for Podman versions 5.8.6 and 6.0.0 at https://github.com/podman-container-tools/podman/commit/a38a9b7d20915c55e6f3c451101ae72d6da33742. If patching is not possible, workarounds include manually copying Quadlet files to the Quadlet directory or removing the destination file before running 'podman quadlet install' without the --replace option. Applying the official patches is the recommended remediation.
CVE-2026-19730: Incomplete Cleanup in Red Hat Red Hat Enterprise Linux 10
Description
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).
CVSS v3.1
Score 4.2medium
Affected software
Red Hat
Red Hat Enterprise Linux 10
Red Hat
Red Hat Enterprise Linux 9
Red Hat
Red Hat Ansible Automation Platform 2
Red Hat
Red Hat Enterprise Linux 8
Red Hat
Red Hat Hardened Images
Red Hat
Red Hat OpenShift Container Platform 4
Red Hat
Red Hat OpenShift Dev Spaces
Red Hat
Red Hat OpenShift Virtualization 4
Red Hat
Red Hat Quay 3
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The 'podman quadlet install --replace' command opens the destination file with O_CREATE|O_WRONLY but omits O_TRUNC, so when the reflink copy fallback uses io.Copy, it performs a non-truncating write. If the original Quadlet file is larger than the new one, leftover content from the original remains, potentially including security-sensitive options like AddCapability or volume mounts. This can cause Podman to fail to enforce configuration changes intended by the administrator. The vulnerable code is in pkg/domain/infra/abi/quadlet.go (lines 338-360) and vendor/go.podman.io/storage/pkg/fileutils/reflink_linux.go (lines 12-19).
Potential Impact
The vulnerability does not allow information leakage or privilege escalation beyond the user's existing permissions. Instead, it causes Podman to fail to remove or update certain security-related configuration options in Quadlet files, potentially leading to unintended container behavior such as retention of capabilities or volume mounts. This could indirectly lead to exposure of host content into containers or compromised container images leaking content later. The overall impact is limited to configuration enforcement failure with moderate confidentiality, integrity, and availability impacts.
Mitigation Recommendations
Patches addressing this issue are available for Podman versions 5.8.6 and 6.0.0 at https://github.com/podman-container-tools/podman/commit/a38a9b7d20915c55e6f3c451101ae72d6da33742. If patching is not possible, workarounds include manually copying Quadlet files to the Quadlet directory or removing the destination file before running 'podman quadlet install' without the --replace option. Applying the official patches is the recommended remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-08-13T13:07:39.303Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-19730","vendor":"Red Hat"}]
Threat ID: 6a7e08efbf8831d5399b798e
Added to database: 08/13/2026, 18:11:59 UTC
Last enriched: 09/23/2026, 02:07:51 UTC
Last updated: 09/28/2026, 13:47:43 UTC
Views: 38
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