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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | — | — |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — | — |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — | — |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | — | — |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | flatpak | 1.18.1-1 | — |
| Debian 13 | flatpak | 1.16.6-1~deb13u2 | — |
| Debian 12 | flatpak | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | flatpak | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | flatpak | No fix yet | — |
| Ubuntu Pro 22.04 LTS | flatpak | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | flatpak +4 | 1.16.0-9.el10_2.4 | RHSA-2026:80498 |
| RHEL 9 | flatpak +4 | 1.12.9-4.el9_8.4 | RHSA-2026:80497 |
| RHEL 8 | flatpak +4 | 1.12.9-7.el8_10 | RHSA-2026:80687 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | flatpak +4 | 1.16.0-9.el10_2.4 | ALSA-2026:80498 |
| AlmaLinux 9 | flatpak +4 | 1.12.9-4.el9_8.4 | ALSA-2026:80497 |
| AlmaLinux 8 | flatpak +4 | 1.12.9-7.el8_10 | ALSA-2026:80687 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | flatpak | 1.16.0-9.el10_2.4 | RLSA-2026:80498 |
| Rocky Linux 9 | flatpak | 1.12.9-4.el9_8.4 | RLSA-2026:80497 |
| Rocky Linux 8 | flatpak | 1.12.9-7.el8_10 | RLSA-2026:80687 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES 15 SP6 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES for SAP 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
| SLE HPC 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | flatpak +4 | 1.16.0-9.el10_2.4 | ELSA-2026-80498 |
| Oracle Linux 9 | flatpak +4 | 1.12.9-4.el9_8.4 | ELSA-2026-80497 |
| Oracle Linux 8 | flatpak +4 | 1.12.9-7.el8_10 | ELSA-2026-80687 |
Advisories 15
- WID-SEC-2026-3861 Red Hat Enterprise Linux (flatpak): Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- SUSE-SU-2026:5127-1 Security update for flatpak SUSE / openSUSE Security Updates · Nov 7, 2026
- SUSE-SU-2026:4944-1 Security update for flatpak SUSE / openSUSE Security Updates · Oct 31, 2026
- ALSA-2026:80497 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:80498 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:80687 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:80497 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2026:80498 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2026:80687 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RLSA-2026:80497 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- RLSA-2026:80498 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- RLSA-2026:80687 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- ELSA-2026-80498 Important: flatpak security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
- ELSA-2026-80497 Important: flatpak security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
- ELSA-2026-80687 Important: flatpak security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
References
- RHSA-2026:80497 vendor-advisory
- RHSA-2026:80498 vendor-advisory
- RHSA-2026:80687 vendor-advisory
- RHSA-2026:89733 vendor-advisory
- RHSA-2026:90364 vendor-advisory
- RHSA-2026:92221 vendor-advisory
- RHSA-2026:92369 vendor-advisory
- RHSA-2026:95493 vendor-advisory
- RHSA-2026:98112 vendor-advisory
- RHSA-2026:98127 vendor-advisory
- RHSA-2026:98490 vendor-advisory
- RHSA-2026:98595 vendor-advisory
- RHSA-2026:99010 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-96280 vdb-entry
- RHBZ#2539419 issue-tracking
- https://github.com/flatpak/flatpak/security/advisories/GHSA-jr92-2v97-wgvc