CVE-2026-59691: Gstreamer1-plugins-bad-free: gstreamer: rfbsrc/librfb hextile heap out-of-bounds write with 16bpp framebuffer

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-09 · updated 2026-09-02
Weakness: CWE-787

Description

A heap buffer overflow vulnerability was found in GStreamer's rfbsrc plugin. When a client connects to a malicious RFB/VNC server that advertises a 16bpp framebuffer and sends Hextile-encoded updates, the Hextile background fill path writes 32-bit pixel values into a buffer allocated for 16-bit pixels. This type mismatch causes an out-of-bounds heap write that can lead to denial of service (process crash) and potential memory corruption.

Affected products

Red Hat Enterprise Linux 10: all versions — fixed in 0:1.26.7-2.el10_2.6
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:1.24.11-3.el10_0.6
Red Hat Enterprise Linux 6: all versions
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:0.10.23-26.el7_9, 0:1.10.4-7.el7_9
Red Hat Enterprise Linux 8: all versions — fixed in 0:1.16.1-9.el8_10.1
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:1.16.1-4.el8_4.4
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 0:1.16.1-4.el8_4.4
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:1.16.1-4.el8_6.4
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:1.16.1-4.el8_6.4
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:1.16.1-4.el8_8.4
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:1.16.1-4.el8_8.4
Red Hat Enterprise Linux 9: all versions — fixed in 0:1.22.12-7.el9_8.3
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:1.18.4-9.el9_2.5
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:1.22.1-6.el9_4.6
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:1.22.12-5.el9_6.6

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:1.26.7-2.el10_2.6; Red Hat Enterprise Linux 10.0 Extended Update Support 0:1.24.11-3.el10_0.6; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:0.10.23-26.el7_9, 0:1.10.4-7.el7_9; Red Hat Enterprise Linux 8 0:1.16.1-9.el8_10.1; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:1.16.1-4.el8_4.4; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:1.16.1-4.el8_4.4; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:1.16.1-4.el8_6.4; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:1.16.1-4.el8_6.4; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:1.16.1-4.el8_8.4; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:1.16.1-4.el8_8.4; Red Hat Enterprise Linux 9 0:1.22.12-7.el9_8.3; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:1.18.4-9.el9_2.5. Check the vendor advisory for mitigations.

References

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