Is CVE-2026-87876 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-87876 being exploited in the wild.

How severe is CVE-2026-87876?

Low severity, with a CVSS score of 3, published 9 September 2026.

Is there a fix for CVE-2026-87876?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-87876 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-87876?

Check whether you run OpenPrinting Cups at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-87876: CUPS scheduler case-insensitive username comparison in ACL validation

CVE-2026-87876 · Severity: low · CVSS 3 · Published 2026-09-09

CUPS is a widely-used printing system that manages access to network printers through username-based access controls. A flaw in how the scheduler compares usernames allows attackers in certain configurations to bypass printer access restrictions and unauthorized filtering of private attributes by exploiting case-sensitive/insensitive comparison logic, potentially gaining access to restricted print queues or viewing sensitive print job metadata.

Technologies: OpenPrinting Cups. Vendors: OpenPrinting.

Quick answers

Is CVE-2026-87876 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-87876 being exploited in the wild.
How severe is CVE-2026-87876?: Low severity, with a CVSS score of 3, published 9 September 2026.
Which products and versions are affected?: OpenPrinting Cups <UNKNOWN>.
Is there a fix for CVE-2026-87876?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-87876 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-87876?: Check whether you run OpenPrinting Cups at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in CUPS's scheduler due to two case-insensitive string comparisons performed on request-derived usernames outside the main authorization code path. These comparisons occur in printer ACL (Access Control List) validation and private-attribute filtering logic. An attacker can craft usernames that differ only in case (e.g., "admin" vs "Admin") to bypass username-based access controls, provided the system is configured to enforce such controls. The flaw requires network access to a CUPS printer server and knowledge of valid usernames. A patch addressing the comparison logic is expected from the CUPS maintainers.

Affected products

OpenPrinting CUPS <UNKNOWN>

Timeline

2026-09-09: disclosed

References

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