# CVE-2026-87875: Cups: openprinting cups: heap out-of-bounds read in cupsutf32toutf8() via missing source-length bound

Status: published. Published: 2026-09-09. Updated: 2026-11-06.

The cupsUTF32ToUTF8() function in CUPS's cups/transcode.c lacks a source-length bound and can read past the end of the source buffer, resulting in a heap out-of-bounds read. This is reachable via SNMP supply-description parsing in backend/snmp-supplies.c with attacker-controlled content.

## Remediation

- workaround: Fixed on upstream master branch with commit 0c6842f and for versions 2.4.x with commit 2b1dc17. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Hardened Images (cups-main): ≥ 2.4.19-4.1.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (rhel9/cups): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.39% as of 2026-11-05; percentile 33.52%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-125

## Exploit evidence

- exploit: https://github.com/OpenPrinting/cups/security/advisories/GHSA-559w-7676-3xrq (ADP: CISA-ADP)

## References

- https://access.redhat.com/errata/RHSA-2026:66600 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-87875 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2530994 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/OpenPrinting/cups/commit/0c6842fc615e8afa284136a092da8178abf5f142 (CNA: redhat)

- https://github.com/OpenPrinting/cups/commit/2b1dc178a2d2325135b855142e384f4e8c42d8e4 (CNA: redhat)

- https://github.com/OpenPrinting/cups/security/advisories/GHSA-559w-7676-3xrq (CNA: redhat)

- https://github.com/OpenPrinting/cups/security/advisories/GHSA-559w-7676-3xrq (ADP: CISA-ADP; exploit)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-87875; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-87875; retrieved 2026-11-06; source updated Not reported

Revision: 2712bf70b5441aeecbacd5730ca0a4a06324efafd62d44b0831c9e69ea72fb04

Canonical: https://y2.dev/cve/CVE-2026-87875

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