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Fencer Vulns
high 7.5

CVE-2026-96280 json

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

published 2026-09-27 42 d ago modified 2026-11-06 3 d ago also EUVD-2026-88015

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

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, 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.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:1.16.0-9.el10_2.4
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:1.16.0-5.el10_0.6
  • Red Hat Red Hat Enterprise Linux 8 0:1.12.9-7.el8_10
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:1.12.9-1.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:1.12.9-1.el8_6.1
  • Red Hat Red Hat Enterprise Linux 9 0:1.12.9-4.el9_8.4
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:1.12.7-5.el9_2.5
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:1.12.9-3.el9_4.5
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:1.12.9-4.el9_6.5
  • flatpak Debian 13 1.16.6-1~deb13u2
  • flatpak Debian 14 1.18.1-1

debian advisories DEBIAN-CVE-2026-96280

  • flatpak RHEL 8 1.12.9-7.el8_10
  • flatpak-libs RHEL 8 1.12.9-7.el8_10
  • flatpak-selinux RHEL 8 1.12.9-7.el8_10
  • flatpak-session-helper RHEL 8 1.12.9-7.el8_10
  • flatpak RHEL 10.2 1.16.0-9.el10_2.4
  • flatpak-libs RHEL 10.2 1.16.0-9.el10_2.4
  • flatpak-selinux RHEL 10.2 1.16.0-9.el10_2.4
  • flatpak-session-helper RHEL 10.2 1.16.0-9.el10_2.4

red hat advisories RHSA-2026:80687RHSA-2026:80498RHSA-2026:80497

  • flatpak SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 1.16.6-150500.3.21.1
  • flatpak SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Desktop Applications 15 SP7 1.16.6-150600.3.12.1

suse advisories SUSE-SU-2026:5127-1SUSE-SU-2026:4944-1

  • flatpak AlmaLinux 9 1.12.9-4.el9_8.4
  • flatpak-libs AlmaLinux 9 1.12.9-4.el9_8.4
  • flatpak-selinux AlmaLinux 9 1.12.9-4.el9_8.4
  • flatpak-session-helper AlmaLinux 9 1.12.9-4.el9_8.4
  • flatpak AlmaLinux 10 1.16.0-9.el10_2.4
  • flatpak-libs AlmaLinux 10 1.16.0-9.el10_2.4
  • flatpak-selinux AlmaLinux 10 1.16.0-9.el10_2.4
  • flatpak-session-helper AlmaLinux 10 1.16.0-9.el10_2.4

almalinux advisories ALSA-2026:80497ALSA-2026:80498ALSA-2026:80687

  • flatpak Rocky Linux 10 1.16.0-9.el10_2.4
  • flatpak Rocky Linux 9 1.12.9-4.el9_8.4
  • flatpak Rocky Linux 8 1.12.9-7.el8_10

rocky linux advisories RLSA-2026:80498RLSA-2026:80497RLSA-2026:80687

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-96280 updated cvss 7.5

flatpak: flatpak: Buffer overflow in OCI delta stream path names on 32-bit systems

  • Red Hat Enterprise Linux 7 flatpak, flatpak-libs, flatpak-builder
    affected: workaround, no fix available “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.”
  • Red Hat CodeReady Linux Builder EUS (v.9.6) flatpak 1.12.9-4.el9_6.5, flatpak-session-helper 1.12.9-4.el9_6.5
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:89733
  • Red Hat Enterprise Linux AppStream (v. 8) flatpak 1.12.9-7.el8_10, flatpak-libs 1.12.9-7.el8_10, flatpak-selinux 1.12.9-7.el8_10, flatpak-session-helper 1.12.9-7.el8_10
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80687
  • Red Hat Enterprise Linux AppStream (v. 9) flatpak 1.12.9-4.el9_8.4, flatpak-libs 1.12.9-4.el9_8.4, flatpak-selinux 1.12.9-4.el9_8.4, flatpak-session-helper 1.12.9-4.el9_8.4
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80497
  • Red Hat Enterprise Linux AppStream (v. 10) flatpak 1.16.0-9.el10_2.4, flatpak-libs 1.16.0-9.el10_2.4, flatpak-selinux 1.16.0-9.el10_2.4, flatpak-session-helper 1.16.0-9.el10_2.4
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80498
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) flatpak 1.12.9-1.el8_6.1, flatpak-libs 1.12.9-1.el8_6.1, flatpak-selinux 1.12.9-1.el8_6.1, flatpak-session-helper 1.12.9-1.el8_6.1
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:95493
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) flatpak 1.12.7-5.el9_2.5, flatpak-libs 1.12.7-5.el9_2.5, flatpak-selinux 1.12.7-5.el9_2.5, flatpak-session-helper 1.12.7-5.el9_2.5
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:92369
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) flatpak 1.12.9-3.el9_4.5, flatpak-libs 1.12.9-3.el9_4.5, flatpak-selinux 1.12.9-3.el9_4.5, flatpak-session-helper 1.12.9-3.el9_4.5
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:90364
show 7 more
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) flatpak 1.16.0-5.el10_0.6, flatpak-libs 1.16.0-5.el10_0.6, flatpak-selinux 1.16.0-5.el10_0.6, flatpak-session-helper 1.16.0-5.el10_0.6
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:92221
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) flatpak 1.12.9-4.el9_6.5, flatpak-libs 1.12.9-4.el9_6.5, flatpak-selinux 1.12.9-4.el9_6.5, flatpak-session-helper 1.12.9-4.el9_6.5
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:89733
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) flatpak 1.12.9-1.el8_6.1, flatpak-libs 1.12.9-1.el8_6.1, flatpak-selinux 1.12.9-1.el8_6.1, flatpak-session-helper 1.12.9-1.el8_6.1
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:95493
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) flatpak 1.12.9-4.el9_8.4, flatpak-session-helper 1.12.9-4.el9_8.4
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80497
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) flatpak-devel 1.16.0-9.el10_2.4, flatpak-debuginfo 1.16.0-9.el10_2.4, flatpak-debugsource 1.16.0-9.el10_2.4, flatpak-libs-debuginfo 1.16.0-9.el10_2.4, flatpak-tests-debuginfo 1.16.0-9.el10_2.4, flatpak-session-helper-debuginfo 1.16.0-9.el10_2.4
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80498
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) flatpak-devel 1.16.0-5.el10_0.6, flatpak-debuginfo 1.16.0-5.el10_0.6, flatpak-debugsource 1.16.0-5.el10_0.6, flatpak-libs-debuginfo 1.16.0-5.el10_0.6, flatpak-tests-debuginfo 1.16.0-5.el10_0.6, flatpak-session-helper-debuginfo 1.16.0-5.el10_0.6
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:92221
  • Red Hat Enterprise Linux CRB (v. 8) flatpak 1.12.9-7.el8_10, flatpak-session-helper 1.12.9-7.el8_10
    fixed: vendor fix “Only install applications from trusted OCI registries. Flatpak remotes using the default OSTree transport are not affected.” RHSA-2026:80687

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
40 d ago

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8
  • 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 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
  • Red Hat Red Hat Enterprise Linux 7

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.