CVE-2026-59691 is a vulnerability in Red Hat Enterprise Linux (RHEL)
Published on July 9, 2026
Gstreamer: gstreamer: rfbsrc/librfb hextile heap out-of-bounds write with 16bpp framebuffer
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.
Vulnerability Analysis
CVE-2026-59691 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public. 2 days later.
Weakness Type
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-59691 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-59691
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