CVE-2026-55480Hinoki check available

Root-file overwrite via predictable PPD tempfile symlinks

Published Oct 15, 2026 · Updated Oct 15, 2026

Symlink following in OpenPrinting CUPS before 2.4.20 allows local users to overwrite root-writable files via a PPD tempfile race. In scheduler/ipp.c, copy_model() opens a connection-number-derived path as root without O_EXCL or O_NOFOLLOW, following planted symlinks and writing generated PPD data. Exploitation requires lp-group write access to TempDir, winning the race, and a privileged printer-addition or modification operation; the resulting truncation or overwrite damages file integrity or availability.

CVSS severity5.7
Medium
EPSS probability0.16%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Symlink following in OpenPrinting CUPS before 2.4.20 allows local users to overwrite root-writable files via a PPD tempfile race. In scheduler/ipp.c, copy_model() opens a connection-number-derived path as root without O_EXCL or O_NOFOLLOW, following planted symlinks and writing generated PPD data. Exploitation requires lp-group write access to TempDir, winning the race, and a privileged printer-addition or modification operation; the resulting truncation or overwrite damages file integrity or availability.

The record

CVE
CVE-2026-55480
Published
Oct 15, 2026
Updated
Oct 15, 2026
Vendor
OpenPrinting
Product
CUPS
Classifications
CWE-377, CWE-59, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.4.20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

OpenPrinting · CUPSversion=< 2.4.20

Published CVSS scores

5.7OpenPrintingCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H
6.3SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
5.8SUSECVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-377Insecure Temporary File
CWE-59Improper Link Resolution Before File Access ('Link Following')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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