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.
References10
- access.redhat.com/errata/RHSA-2026:80497
- access.redhat.com/errata/RHSA-2026:80498
- access.redhat.com/errata/RHSA-2026:80687
- access.redhat.com/errata/RHSA-2026:89733
- access.redhat.com/errata/RHSA-2026:90364
- access.redhat.com/errata/RHSA-2026:92221
- access.redhat.com/errata/RHSA-2026:92369
- access.redhat.com/errata/RHSA-2026:95493
- access.redhat.com/security/cve/CVE-2026-96280
- bugzilla.redhat.com/show_bug.cgi?id=2539419
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 48 · as of 9 November 2026
- CWE
- CWE-197
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