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.
Problem types
Product status
Timeline
| 2026-07-06: | Reported to Red Hat. |
| 2026-07-08: | Made public. |
Credits
Red Hat would like to thank Clouditera Security (Clouditera), NSFOCUS (NSFOCUS), and Z.ai Security (Z.ai) for reporting this issue.
References
access.redhat.com/security/cve/CVE-2026-59691
bugzilla.redhat.com/show_bug.cgi?id=2497343 (RHBZ#2497343)
gitlab.freedesktop.org/...amer-security/-/merge_requests/100
gitlab.freedesktop.org/gstreamer/gstreamer/-/work_items/5173