CVE-2025-64503VulnerabilityPublished 12 Nov 2025

CVE-2025-64503: OpenPrinting cups-filters · Out-of-bounds Write

Affects OpenPrinting cups-filtersSource CVE Database V5

Not known to be exploited · CVSS 4.0 Medium : upgrade to 2.1.2 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.0Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.1.2

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade openprinting/cups-filters to 2.1.2.

Affected software

Product	Affected	Fixed in
GitHubopenprinting/cups-filters`pkg:github/openprinting/cups-filters`Other threats	Affected <2.1.2	Fixed in 2.1.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately upgrade cups-filters to version 1.28.18 or later and libcupsfilters to 2.1.2 or later to apply the official patch that addresses the integer overflow and buffer allocation issues. Until upgrades can be performed, restrict local access to printing services and limit PDF submissions to trusted users to reduce exposure. Implement monitoring and alerting on printing service crashes or abnormal behavior that could indicate exploitation attempts. Employ application whitelisting or sandboxing for the pdftoraster tool to contain potential impacts. Review and harden print server configurations to minimize attack surface, including disabling unnecessary backends or filters. Conduct internal audits to identify systems running vulnerable versions and prioritize patching based on criticality. Educate users about submitting only trusted print jobs and consider network segmentation to isolate print servers from less trusted endpoints. Finally, maintain up-to-date backups of print server configurations and logs to facilitate recovery and forensic analysis if needed.

Description

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.

Impact

For European organizations, this vulnerability primarily poses a risk to the availability and stability of printing services running on Linux or Unix systems using vulnerable cups-filters versions. Exploitation could allow an attacker with local access to submit a malicious PDF file that triggers a crash or denial-of-service in the printing pipeline, potentially disrupting business operations that rely on printing. While confidentiality and integrity impacts are not evident, the loss of printing availability can affect administrative, operational, and compliance workflows, especially in sectors like government, finance, healthcare, and manufacturing where printed documentation remains critical. Organizations with centralized print servers or shared network printers are particularly at risk, as a single exploit could impact multiple users. The lack of required privileges lowers the barrier for exploitation in multi-user environments. Although no remote exploitation is indicated, insider threats or compromised endpoints could leverage this flaw. The medium severity rating suggests moderate urgency but should not be ignored given the essential nature of printing services in many European enterprises.

CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Nov 2025, 23:14 UTC

WeaknessesCWE-787

Technical details

References

Community reviews

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