Samba: samba: remote code execution in printing subsystem via unescaped job description

Summary

CVE	CVE-2026-4480
State	PUBLISHED
Assigner	redhat
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-05-26 15:16:40 UTC
Updated	2026-06-03 06:16:34 UTC
Description	A flaw was found in the Samba printing subsystem. Samba passes the client-controlled job description string to the command configured with the "print command" setting via the "%J" substitution character without escaping shell meta characters. A remote attacker could exploit this vulnerability by sending a specially crafted print job description that contains unescaped shell characters. This could lead to remote code execution on the affected system.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.001640000 probability, percentile 0.371010000 (date 2026-06-02)

Problem Types: CWE-78 | CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	9.8	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
3.1	[email protected]	Secondary	8.5	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`
3.1	CNA	CVSS	8.5	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Operating System	Redhat	Enterprise Linux	10.0	All	All	All
Operating System	Redhat	Enterprise Linux	7.0	All	All	All
Operating System	Redhat	Enterprise Linux	8.0	All	All	All
Operating System	Redhat	Enterprise Linux	9.0	All	All	All
Application	Redhat	Openshift Container Platform	4.0	All	All	All
Application	Samba	Samba	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Red Hat	Red Hat Enterprise Linux 8	unaffected 0:4.19.4-16.el8_10 * rpm	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 8	unaffected 0:4.19.4-16.el8_10 * rpm	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 10	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 6	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 6	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 7	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 9	Not specified	Not specified
CNA	Red Hat	Red Hat OpenShift Container Platform 4	Not specified	Not specified

References

Reference	Source	Link	Tags
bugzilla.samba.org/show_bug.cgi	[email protected]	bugzilla.samba.org	Issue Tracking, Vendor Advisory
access.redhat.com/errata/RHSA-2026:22644	[email protected]	access.redhat.com
access.redhat.com/security/cve/CVE-2026-4480	[email protected]	access.redhat.com	Mitigation, Third Party Advisory
bugzilla.redhat.com/show_bug.cgi	[email protected]	bugzilla.redhat.com	Issue Tracking, Third Party Advisory
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Arjun Basnet (Securin Labs), John Walker (ZeroPath), and Ron Ben Yizhak (SafeBreach) for reporting this issue. (en)

Additional Advisory Data

Source	Time	Event
CNA	2026-03-27T13:35:42.879Z	Reported to Red Hat.
CNA	2026-05-26T13:43:46.237Z	Made public.

Workarounds

CNA: Remove ```"%J"``` from the "print command" in ```smb.conf``` entry.

There are currently no legacy QID mappings associated with this CVE.