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CVE-2026-87876

Cups: openprinting cups: remaining case-insensitive username matching in scheduler side paths (cve-2026-27447 follow-up)

Products / packages Red Hat Hardened Images · Red Hat Enterprise Linux 10 · Red Hat Enterprise Linux 6 · 4 more

Published

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Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 15/11/2026, 03:00:33 UTC
redhat · CVSS:3.1 · 3
Assessment vectorCVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N

Severity

low3.0

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Exploit reference published

Source-linked evidence; not proof of attacks in the wild or independent validation.

Remediation

Source guidance available

Review the recorded instructions. Guidance may be a workaround rather than a fixed version.

What this means

CUPS's scheduler has case-insensitive username comparisons that could allow bypass of access controls. The issue affects Red Hat Enterprise Linux versions. An attacker may exploit this weakness in certain configurations.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Red Hat · redhat

Red Hat Hardened Images

1 range
redhat version evidence

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affected

unaffected

2.4.19-4.2.hum1 → before *

rpm versions

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:hummingbird:1

Red Hat · redhat

Red Hat Enterprise Linux 10

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:10

Red Hat · redhat

Red Hat Enterprise Linux 6

0 ranges
redhat version evidence

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affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/o:redhat:rhel_els:6

Red Hat · redhat

Red Hat Enterprise Linux 7

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/o:redhat:rhel_els:7

Red Hat · redhat

Red Hat Enterprise Linux 8

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:8

Red Hat · redhat

Red Hat Enterprise Linux 9

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:9

Red Hat · redhat

Red Hat Enterprise Linux 9

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:9

Red Hat · redhat

Red Hat OpenShift Container Platform 4

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:openshift:4
Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when/if they become available.

redhat guidance ↗

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

The sources identify public exploit references. We have not independently tested them; their availability does not establish exploitation in the wild.

OpenPrinting/cups · security/advisories/GHSA-r8jp-q6fh-g5r2 ↗Attributed to CISA-ADP

Original source description

Read the full publisher description

Two case-insensitive comparisons on request-derived usernames outside the main authorization path in CUPS's scheduler (printer ACL validation and private-attribute filtering) could allow bypass of username-based access controls in certain configurations.

References

6 sources
access.redhat.com/errata/RHSA-2026:67568
Vendor advisoryredhat
access.redhat.com/security/cve/CVE-2026-87876
Security advisoryredhat
bugzilla.redhat.com/show_bug.cgi
Source referenceredhat
OpenPrinting/cups · commit 88e67c0
Patchredhat
OpenPrinting/cups · commit f56844d
Patchredhat
OpenPrinting/cups · security/advisories/GHSA-r8jp-q6fh-g5r2
Public exploit referenceredhat · CISA-ADP

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-87876

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-178 ↗

Improper Handling of Case Sensitivity

redhat

Related →
Contributing organizations · 2
redhat

Assigning organization

2026-11-07
CISA-ADP

Additional data publisher

2026-09-09

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
  1. CVE · CVE-2026-87876

    Observed 2026-11-07T05:15:45.963Z · upstream updated 2026-11-07T05:01:59.159Z

    Remediation guidance changed

    before

    [
  {
    "text": "Fixed on upstream master branch with commit f56844d and for versions 2.4.x with commit 88e67c0.",
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-87876"
  }
]

    after

    [
  {
    "text": "Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when/if they become available.",
    "source": "redhat",
    "url": "https://www.cve.org/CVERecord?id=CVE-2026-87876"
  }
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.