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Verified reproduction

CVE-2026-4480: Samba’s printing subsystem allows OS command injection via unescaped job description (%J), enabling remote code execution through crafted print jobs.

CVE-2026-4480 is verified against samba-team/samba · generic affected versions: All Samba versions before the fix (advisory says 'All versions') vulnerability class: RCE This high reproduction includes runnable sandbox proof, artifacts, and a plain-text agent view under REPRO-2026-00285.

REPRO-2026-00285 samba-team/samba · generic RCE Variant found Jul 13, 2026 .txt
Severity HIGH
Confidence HIGH
Reproduced in 28m 55s
Tool calls 343
Spend $8.77
Affected All Samba versions before the fix (advisory says 'All versions')
$ pruva-verify REPRO-2026-00285
or curl -O https://pruva.dev/api/v1/reproductions/REPRO-2026-00285/artifacts/bundle/repro/reproduction_steps.sh && chmod +x reproduction_steps.sh && ./reproduction_steps.sh
Run in a VM or disposable container. This exploits a real vulnerability.
02 · The vulnerability

A flaw in Samba’s printing subsystem passes the client-controlled job description string to the configured print command using the %J substitution without escaping shell metacharacters. An unauthenticated/remote attacker who can submit a print job can inject shell commands, leading to remote code execution on the Samba server.

03 · Root cause
Variant analysis
04 · Reproduction transcript

The agent's step-by-step process — every tool call, every handoff, the moment the exploit fired. Phases: support triages the advisory · repro reproduces it · vuln_variant confirms the fix blocks it · judge verifies.

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05 · Artifacts

Scripts, logs, diffs, and output captured during the reproduction.