CVE-2026-34990: CWE-287: Improper Authentication in OpenPrinting cups
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.
AI Analysis
Technical Summary
OpenPrinting CUPS versions up to 2.4.16 contain an authentication bypass vulnerability (CWE-287) where a local unprivileged user can coerce the cupsd service into authenticating to an attacker-controlled localhost IPP service using a reusable 'Authorization: Local ...' token. This token grants the ability to perform administrative actions on localhost, including creating a local printer queue with a file URI despite policy restrictions. Exploiting this allows arbitrary root file overwrite, demonstrated by dropping a sudoers fragment to achieve root command execution. The vulnerability has a CVSS 4.0 score of 5.0 (medium severity). No patches or vendor advisories indicating fixes are currently available.
Potential Impact
An attacker with local unprivileged access can escalate privileges to root by exploiting the improper authentication mechanism in CUPS. This includes the ability to overwrite arbitrary root-owned files, potentially leading to full system compromise. The vulnerability affects all CUPS versions up to 2.4.16. There are no known public exploits in the wild at this time.
Mitigation Recommendations
At the time of this report, no official patches or fixes are available for this vulnerability. Users should monitor the OpenPrinting project for updates and advisories. Until a fix is released, restricting local user access and limiting exposure to untrusted local users may reduce risk. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
CVE-2026-34990: CWE-287: Improper Authentication in OpenPrinting cups
Description
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.
CVSS v4.0
Score 5.0medium
Affected software
pkg:github/openprinting/cupsRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OpenPrinting CUPS versions up to 2.4.16 contain an authentication bypass vulnerability (CWE-287) where a local unprivileged user can coerce the cupsd service into authenticating to an attacker-controlled localhost IPP service using a reusable 'Authorization: Local ...' token. This token grants the ability to perform administrative actions on localhost, including creating a local printer queue with a file URI despite policy restrictions. Exploiting this allows arbitrary root file overwrite, demonstrated by dropping a sudoers fragment to achieve root command execution. The vulnerability has a CVSS 4.0 score of 5.0 (medium severity). No patches or vendor advisories indicating fixes are currently available.
Potential Impact
An attacker with local unprivileged access can escalate privileges to root by exploiting the improper authentication mechanism in CUPS. This includes the ability to overwrite arbitrary root-owned files, potentially leading to full system compromise. The vulnerability affects all CUPS versions up to 2.4.16. There are no known public exploits in the wild at this time.
Mitigation Recommendations
At the time of this report, no official patches or fixes are available for this vulnerability. Users should monitor the OpenPrinting project for updates and advisories. Until a fix is released, restricting local user access and limiting exposure to untrusted local users may reduce risk. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-31T19:38:31.618Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d031770a160ebd925d201a
Added to database: 04/03/2026, 21:30:31 UTC
Last enriched: 05/28/2026, 21:22:23 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 174
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