Description
OpenPrinting CUPS before 2.4.20 contains a double-free in printer-class management. When CUPS-Add-Modify-Class replaces an existing class member list, add_class() frees pclass->printers without clearing the pointer. If subsequent validation fails, the class retains the dangling pointer; CUPS-Delete-Class subsequently frees the same allocation in cupsdDeletePrinter(). A client authorized to modify and delete classes can cause scheduler-wide denial of service. The default policy requires @SYSTEM privileges.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| OpenPrinting | CUPS | 1.4.8 – < 2.4.20 | 2.4.20 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | cups | 2.4.20-1 | — |
| Debian 13 | cups | No fix yet | — |
| Debian 12 | cups | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | cups | No fix yet | — |
| Ubuntu 26.04 LTS | cups | No fix yet | — |
| Ubuntu 24.04 LTS | cups | No fix yet | — |
| Ubuntu 22.04 LTS | cups | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | cups | No fix yet | — |
| Ubuntu Pro 18.04 LTS | cups | No fix yet | — |
| Ubuntu Pro 16.04 LTS | cups | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | cups +7 | 2.4.19-4.5.hum1 | RHSA-2026:81410 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | cups +7 | 1:2.4.20-1.amzn2023.0.1 | ALAS2023-2026-3415 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | cups | No fix yet | — |
Advisories 3
- ALAS2023-2026-3415 Moderate: cups security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 9, 2026
- RHSA-2026:81410 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- WID-SEC-2026-3742 CUPS: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Oct 12, 2026