CVE-2026-96280

critical

Description

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.

References

https://github.com/flatpak/flatpak/security/advisories/GHSA-jr92-2v97-wgvc

https://bugzilla.redhat.com/show_bug.cgi?id=2539419

https://access.redhat.com/security/cve/CVE-2026-96280

Details

Source: Mitre, NVD

Published: 2026-09-27

Updated: 2026-09-27

Risk Information

CVSS v2

Base Score: 7.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00599