CVE-2026-61702 is a path traversal vulnerability in OpenPrinting CUPS prior to version 2.4.20. It allows an attacker to use crafted IPP attributes to escape the intended banner directory and cause the scheduler to read arbitrary files accessible via symlinks. The contents of these files can then be copied into a job-sheet spool object and potentially exposed to an attacker-observable endpoint. This vulnerability is fixed in version 2.4.20.
CVE-2026-55480 is a vulnerability in OpenPrinting CUPS prior to version 2.4.20 where a race condition in the copy_model() function allows a privileged process to follow a symlink and overwrite arbitrary root-writable files. This occurs because a temporary file path is created in a group-writable directory without secure flags, enabling symlink attacks. Exploitation requires an attacker with lp-group write access and a privileged add-printer or modify-printer operation. The issue is fixed in version 2.4.20.
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the cupsdCreateJob option-string builder in scheduler/job.c maps attacker-controlled destination-uri and pre-dial-string values from a configured fax queue to the phone and faxPrefix options. Unlike ordinary IPP job attributes, these mapped fax values bypass the control-character sanitizer and are copied directly into the filter options argument. A user permitted to submit a job can therefore inject control characters into the downstream option stream. The reporter states that a downstream fax filter passing these values to a shell or modem command could execute code as lp, while the maintainer states that CUPS has no confidentiality or integrity impact because the only known code-executing filter is optional Foomatic and addressed separately, leaving possible disruption of the affected queue. This issue is fixed in version 2.4.20.
OpenPrinting CUPS before 2.4.20 contains a NULL pointer dereference caused by repeated IPP group tags in job-creation requests. IPP parsing creates unnamed separator attributes with IPP_TAG_ZERO, but add_job() converts these separators to IPP_TAG_JOB. During job startup, get_options()/ipp_length() subsequently calls strlen() on a NULL attribute name, terminating cupsd and disrupting all queues. A single crafted Print-Job request can trigger the crash when the client can reach the scheduler and submit jobs to an accepting, enabled queue supporting the submitted document format. Anonymous submission is possible when permitted by listener and access-control configuration.
OpenPrinting CUPS before 2.4.20 contains a NULL pointer dereference in cupsdCheckJobs() when a job marked job-held-on-create refers to a temporary printer that has been automatically deleted. Temporary-printer cleanup can remove the destination without canceling its held jobs, and the scheduler dereferences the NULL result of cupsdFindDest() while checking holding_new_jobs. This terminates cupsd and interrupts all queues managed by that process. In some plausible scenarios, an unprivileged submission can trigger this.
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.
CVE-2026-107885 is a resource-exhaustion vulnerability in OpenPrinting CUPS versions up to 2.4.20. It arises from improper handling of submission timeouts in the cupsdCheckJobs() function. The scheduler suppresses timeout processing for all pending jobs if any client connection has an ongoing Send-Document operation, regardless of job association. This allows a client to hold incomplete HTTP requests, preventing unrelated jobs from timing out. As a result, incomplete jobs can accumulate until the MaxJobs limit is reached, causing denial of service by rejecting new print submissions.
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the backend/ipp.c quote_string() function preserves carriage-return and line-feed characters in a remote printer-controlled marker-message before report_attr() writes the value to the scheduler status stream. The scheduler can parse an injected newline as a separate PPD: control line and persist an attacker-selected PPD keyword. The reporter demonstrated that a later print job on a Foomatic-backed queue could consume an injected FoomaticRIPCommandLine value and execute in the filter context as lp. This issue is fixed in version 2.4.20.
CVE-2026-41079 is a medium severity vulnerability in OpenPrinting CUPS versions prior to 2.4.17. It involves an out-of-bounds read triggered by a crafted SNMP response sent to the CUPS SNMP backend. This flaw allows reading up to 176 bytes beyond a stack buffer, leaking memory that is converted to UTF-8 and exposed as printer supply descriptions. These leaked strings can be viewed by authenticated users through IPP Get-Printer-Attributes responses and the CUPS web interface. The vulnerability does not impact integrity or availability and requires network adjacency but no privileges or user interaction. A fix is available in version 2.4.17.
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 for code execution.
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 can repeat the crash for sustained denial of service.
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 time of publication, there are no publicly available patches.
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 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 queued jobs disappear. At time of publication, there are no publicly available patches.
CVE-2026-34990 is an improper authentication vulnerability in OpenPrinting CUPS versions 2.4.16 and earlier. A local unprivileged user can trick the CUPS daemon into authenticating to a malicious localhost IPP service using a reusable authorization token. This token allows the attacker to perform administrative requests locally, including creating a printer queue with a file URI that bypasses normal policy restrictions. Exploiting this flaw can lead to arbitrary root file overwrites, enabling privilege escalation to root. No patches or official fixes are available at the time of publication.
CVE-2026-27447 is an authorization bypass vulnerability in OpenPrinting CUPS versions 2.4.16 and earlier. The issue arises from case-insensitive username comparison during authorization checks in the CUPS daemon, allowing an unprivileged user to perform restricted operations by using a username differing only in letter case from an authorized user. No patches or official fixes are available at the time of publication. The vulnerability has a medium severity rating with a CVSS score of 4.8.
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 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.
cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. In versions 2.0.1 and prior, a heap-buffer-overflow vulnerability in the rastertopclx filter causes the program to crash with a segmentation fault when processing maliciously crafted input data. This issue can be exploited to trigger memory corruption, potentially leading to arbitrary code execution. This issue has been patched via commit 956283c.
cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. In cups-filters prior to 1.28.18, by crafting a PDF file with a large `MediaBox` value, an attacker can cause CUPS-Filter 1.x’s `pdftoraster` tool to write beyond the bounds of an array. First, a PDF with a large `MediaBox` width value causes `header.cupsWidth` to become large. Next, the calculation of `bytesPerLine = (header.cupsBitsPerPixel * header.cupsWidth + 7) / 8` overflows, resulting in a small value. Then, `lineBuf` is allocated with the small `bytesPerLine` size. Finally, `convertLineChunked` calls `writePixel8`, which attempts to write to `lineBuf` outside of its buffer size (out of bounds write). In libcupsfilters, the maintainers found the same `bytesPerLine` multiplication without overflow check, but the provided test case does not cause an overflow there, because the values are different. Commit 50d94ca0f2fa6177613c97c59791bde568631865 contains a patch, which is incorporated into cups-filters version 1.28.18.
