CVE-2026-19730
mediumpriority · track · 0EPSS 0.001 · 3 %ileDEEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.9–4.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (10)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-2846Podman: Schwachstelle ermöglicht nicht spezifizierten Angriff und Offenlegung von InformationenDeutsch2026-08-13csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle in Podman ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, und um Informationen offenzulegen..
- GHSA-fx76-2j3w-2mx6podman quadlet install --replace does not fully replace the old file2026-09-24ghsa · osvUS
### Impact When running `podman quadlet install --replace` to replace a Quadlet file, if the original Quadlet is larger than the new Quadlet, the file would not be truncated and content from the original would be preserved. 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 (see https://github.com/podman-container-tools/podman/issues/29013). 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. First introduced in commit 0ea4eaee70b7458bcc99d875529761faf5172651 with podman 5.7.0 ### Patches a38a9b7d20915c55e6f3c451101ae72d6da33742 (fixed in 6.0.0) d3adfdeec7d5c9eee5a6978df3bee62a866c958d d4fe9154ec6e32a02d5fcd096c4a27c38f2040f4 (for v5.8 branch, fixed in 5.8.6) ### Workarounds Manually copy the quadlet files to the quadlet directory. ### Credits Podman thanks Christopher Lusk <clusk@northecho.dev> (North Echo Security Research) for reporting the security impact of this problem.
- GO-2026-6588podman quadlet install --replace does not fully replace the old file in github.com/containers/podman2026-10-01vendor · osvUS
podman quadlet install --replace does not fully replace the old file in github.com/containers/podman
also known as (3)
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sources
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references (8)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/CVE-2026-19730enisa_euvd
- https://bugzilla.redhat.com/show_bug.cgi?id=2508234enisa_euvd
- https://github.com/podman-container-tools/podman/issues/29013enisa_euvd
- https://github.com/podman-container-tools/podman/security/advisories/GHSA-fx76-2j3w-2mx6enisa_euvd
- https://access.redhat.com/security/cve/CVE-2026-19730nvd
- https://bugzilla.redhat.com/show_bug.cgi?id=2508234nvd
- https://github.com/podman-container-tools/podman/issues/29013nvd
- https://github.com/podman-container-tools/podman/security/advisories/GHSA-fx76-2j3w-2mx6nvd
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