---
id: CVE-2026-96280
title: >-
  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, …
summary: >-
  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, …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-197
vendor: Red Hat
product: flatpak
affected:
  - flatpak (all versions)
  - flatpak (all versions)
  - flatpak (all versions)
  - flatpak (all versions)
published: '2026-09-27'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T17:17:39.117'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-96280'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:80497'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:80498'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:80687'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-96280'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2539419'
    label: secalert@redhat.com
  - url: 'https://github.com/flatpak/flatpak/security/advisories/GHSA-jr92-2v97-wgvc'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96280.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-96280'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-96280'
  - url: 'https://access.redhat.com/errata/RHSA-2026:89733'
    label: 'RHSA-2026:89733'
  - url: 'https://access.redhat.com/errata/RHSA-2026:90364'
    label: 'RHSA-2026:90364'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00497
epssPercentile: 0.42398
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-29T15:50:48.098460Z'
ingestedAt: '2026-09-27T20:58:01.543Z'
patched:
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_8
  - enterprise_linux_appstream_eus_v_9_6
  - enterprise_linux_appstream_v_9
  - enterprise_linux_codeready_linux_builder_v_10
  - enterprise_linux_crb_v_8
  - codeready_linux_builder_eus_v_9_6
  - enterprise_linux_codeready_linux_builder_v_9
---

## Overview

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

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 7 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96280.json)
- **RHSA-2026:80498** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80498)
- **RHSA-2026:80687** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80687)
- **RHSA-2026:89733** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89733)
- **RHSA-2026:80497** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80497)