Unauthenticated RCE in Samba printing subsystem via %J print command injection
CVE-2026-4480 is a command injection vulnerability in the Samba printing subsystem. When Samba is configured as a print server and the smb.conf "print command" option contains the "%J" substitution character, Samba passes a client-controlled print job description string into the configured shell command without properly escaping shell metacharacters. An attacker can submit a specially crafted print job description containing shell syntax, causing unintended command execution in the context of the print command handler. Samba’s fix removes support for "%J" in "print command" to eliminate this injection path.
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Impact, mitigation & remediation
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Exploits
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No public exploit code observed for this vulnerability.
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Recent activity
21 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A critical unauthenticated remote code execution vulnerability in the Samba printing subsystem caused by unsafe handling of the %J substitution parameter in print command configurations, enabling shell command injection.
A remote code execution vulnerability in the Samba printing subsystem caused by improper escaping of shell metacharacters in the client-controlled print job description passed through the "%J" substitution in the "print command" setting.
An unauthenticated remote code execution vulnerability in the Samba printing subsystem caused by unsafe handling of the %J substitution character in the "print command" setting, allowing client-controlled input to reach a shell command without proper escaping.
A Samba print command injection vulnerability caused by unsafe expansion of '%J' in print command handling, potentially allowing remote code execution via crafted print job names.
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Every observed campaign linking this CVE to a named adversary.
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Cross-references every affected SKU, including bundled OEM variants.
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