CVE Intelligence
Low Injection

CVE-2026-55453 — CUPS ipp backend status-line injection can update queue PPD and lead to conditional RCE as lp via foomatic-rip

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.

Published Oct 15, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • No scoring signals.

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Openprinting
Cups
CVSS base
3.3
Low · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Openprinting Cups).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Openprinting Cups version < 2.4.20 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
3.3 CVSS 3.1 Low 1.8 1.4 security-advisories@github.com via NIST National Vulnerability Database
3.3 CVSS 3.1 Low — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-74 · Injection

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
endpoint telemetry (EDR)application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · openprinting/cups
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 3.3
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · Alertas do Telegram
  • CVE published
    Oct 15, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 15, 2026 – Oct 15, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

4 on the record

Elsewhere on this site

Openprinting
every CVE for this vendor
Injection
same class
CWE-74
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-61702 OpenPrinting CUPS: root-side banner file disclosure 4h
  • CVE-2026-55467 CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix) 4h
  • CVE-2026-55480 CUPS copy_model() creates a predictable PPD tempfile without O_EXCL/O_NOFOLLOW (symlink TOCTOU, lp → root) 4h
  • CVE-2026-107888 OpenPrinting CUPS before 2.4.20 contains a NULL pointer dereference in cupsdCheckJobs() when a... 6d
  • CVE-2026-107890 NULL Pointer Dereference in Openprinting Cups 6d
  • CVE-2026-107886 Double Free in Openprinting Cups 6d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-55453 is "CUPS ipp backend status-line injection can update queue PPD and lead to conditional RCE as lp via foomatic-rip", rated Low. It affects Cups (Openprinting); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 3.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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