What’s Vulnerable › Vulnerabilities

CVE-2026-105326: Cups: cups: argument injection in mailto notifier via notify-recipient-uri

• Severity: low (CVSS 2.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-05 · updated 2026-10-07
• Weakness: CWE-88

Description

An argument injection flaw was found in CUPS. When email notification is configured, the CUPS scheduler accepts printer subscription requests that supply a mailto notify-recipient-uri. The mailto notifier passes the recipient address to the configured sendmail program without ensuring it cannot be interpreted as command-line options. A remote attacker who can reach the CUPS service could supply a crafted recipient value starting with "-" to influence sendmail behavior. Successful exploitation depends on the installed mail transfer agent and CUPS network exposure, and may lead to execution of attacker-controlled commands with the privileges of the CUPS service user.

Affected products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions
• Red Hat Hardened Images: all versions — fixed in 2.4.19-4.3.hum1

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 2.4.19-4.3.hum1. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:77638
• https://access.redhat.com/security/cve/CVE-2026-105326
• https://bugzilla.redhat.com/show_bug.cgi?id=2545835
• https://github.com/OpenPrinting/cups/commit/1244ed9
• https://github.com/OpenPrinting/cups/commit/611d1bd
• https://github.com/OpenPrinting/cups/security/advisories/GHSA-r4wf-366f-f6g3

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