# CVE-2026-96280: Flatpak: flatpak: buffer overflow in oci delta stream path names on 32-bit systems

Status: published. Published: 2026-09-27. Updated: 2026-11-02.

The OCI delta stream parser read sizes as guint64 but passed them to GLib I/O and allocation functions expecting gsize (32 bits on 32-bit systems), causing undersized allocations while subsequent operations use the original 64-bit size, leading to heap buffer overflows. An attacker controlling an OCI registry can craft a delta stream that triggers this during flatpak install/update, potentially achieving code execution on 32-bit systems.

## Remediation

- workaround: Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (flatpak): ≥ 0:1.16.0-9.el10_2.4; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10.0 Extended Update Support (flatpak): ≥ 0:1.16.0-5.el10_0.6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (flatpak): ≥ 0:1.12.9-7.el8_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (flatpak): ≥ 0:1.12.9-4.el9_8.4; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions (flatpak): ≥ 0:1.12.7-5.el9_2.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions (flatpak): ≥ 0:1.12.9-3.el9_4.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.6 Extended Update Support (flatpak): ≥ 0:1.12.9-4.el9_6.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (flatpak): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.57% as of 2026-11-01; percentile 47.23%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-197

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:80497 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:80498 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:80687 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:89733 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:90364 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:92221 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:92369 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-96280 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2539419 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/flatpak/flatpak/security/advisories/GHSA-jr92-2v97-wgvc (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-96280; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-96280; retrieved 2026-11-02; source updated Not reported

Revision: 70da7af18da246eca33a0dab7e5d0840559431b690ebc9444f6e587fe62084b5

Canonical: https://y2.dev/cve/CVE-2026-96280