USN-8405-1 fixed vulnerabilities in CUPS. The update introduced a
regression that cause CUPS to crash when parsing certain large printer PPD
files. This update fixes the problem.
Original advisory details:
Ariel Silver discovered that CUPS incorrectly handled username comparisons
during authorization checks. A local attacker could possibly use this issue
to gain unauthorized access to restricted operations. (CVE-2026-27447)
Asim Viladi Oglu Manizada discovered that CUPS incorrectly handled
notify-recipient-uri values in the RSS notifier. A remote attacker could
possibly use this issue to overwrite lp-writable files and cause a denial
OpenPrinting CUPS: Heap out-of-bounds read in SNMP supply-level polling leaks stack memory to authenticated users
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.17, a network-adjacent attacker can send a crafted SNMP response to the CUPS SNMP backend that causes an out-of-bounds read of up to 176 bytes past a stack buffer. The leaked memory is converted from UTF-16 to UTF-8 and stored as printer supply description strings, which are subsequently visible to authenticated users via IPP Get-Printer-Attributes responses and the CUPS web interface. This vulnerability is fixed in 2.4.17.
CUPS has a use-after-free in `cupsdDeleteTemporaryPrinters` via dangling subscription pointer
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a use-after-free vulnerability exists in the CUPS scheduler (cupsd) when temporary printers are automatically deleted. cupsdDeleteTemporaryPrinters() in scheduler/printers.c calls cupsdDeletePrinter() without first expiring subscriptions that reference the printer, leaving cupsd_subscription_t.dest as a dangling pointer to freed heap memory. The dangling pointer is subsequently dereferenced at multiple code sites, causing a crash (denial of service) of the cupsd daemon. With heap grooming, this can be leveraged fo
CUPS has an integer underflow in `_ppdCreateFromIPP` causes root cupsd crash via negative `job-password-supported`
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, an integer underflow vulnerability in _ppdCreateFromIPP() (cups/ppd-cache.c) allows any unprivileged local user to crash the cupsd root process by supplying a negative job-password-supported IPP attribute. The bounds check only caps the upper bound, so a negative value passes validation, is cast to size_t (wrapping to ~2^64), and is used as the length argument to memset() on a 33-byte stack buffer. This causes an immediate SIGSEGV in the cupsd root process. Combined with systemd's Restart=on-failure, an attacker c
OpenPrinting CUPS: Shared PostScript queue lets anonymous Print-Job requests reach `lp` code execution over the network
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At ti
OpenPrinting CUPS: Heap overflow in `get_options()`
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, there is a heap-based buffer overflow in the CUPS scheduler when building filter option strings from job attribute. At time of publication, there are no publicly available patches.
OpenPrinting CUPS: Path traversal in RSS notify-recipient-uri enables file write outside CacheDir/rss (and clobbering of job.cache)
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, the RSS notifier allows .. path traversal in notify-recipient-uri (e.g., rss:///../job.cache), letting a remote IPP client write RSS XML bytes outside CacheDir/rss (anywhere that is lp-writable). In particular, because CacheDir is group-writable by default (typically root:lp and mode 0770), the notifier (running as lp) can replace root-managed state files via temp-file + rename(). This PoC clobbers CacheDir/job.cache with RSS XML, and after restarting cupsd the scheduler fails to parse the job cache and previously
Media · CVSS 5EPSS 0,29%Código de explotación públicoCorrección disponible
OpenPrinting CUPS: Local print admin token disclosure using temporary printers
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a local unprivileged user can coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable Authorization: Local ... token. That token is enough to drive /admin/ requests on localhost, and the attacker can combine CUPS-Create-Local-Printer with printer-is-shared=true to persist a file:///... queue even though the normal FileDevice policy rejects such URIs. Printing to that queue gives an arbitrary root file overwrite; the PoC below uses that primitive to drop a sudoers fragment a
OpenPrinting CUPS: Authorization bypass via case-insensitive group-member lookup
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, CUPS daemon (cupsd) contains an authorization bypass vulnerability due to case-insensitive username comparison during authorization checks. The vulnerability allows an unprivileged user to gain unauthorized access to restricted operations by using a user with a username that differs only in case from an authorized user. At time of publication, there are no publicly available patches.
OpenPrinting CUPS slow client can halt cupsd, leading to a possible DoS attack
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to version 2.4.15, a client that connects to cupsd but sends slow messages, e.g. only one byte per second, delays cupsd as a whole, such that it becomes unusable by other clients. This issue has been patched in version 2.4.15.
OpenPrinting CUPS vulnerable to stack based out-of-bound write
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to version 2.4.15, a user in the lpadmin group can use the cups web ui to change the config and insert a malicious line. Then the cupsd process which runs as root will parse the new config and cause an out-of-bound write. This issue has been patched in version 2.4.15.