Heap Buffer Overflow in GStreamer’s rfbsrc Plugin Exposes Vulnerability
CVE-2026-59691

7.1HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
9 July 2026

What is CVE-2026-59691?

GStreamer’s rfbsrc plugin exhibits a vulnerability caused by a heap buffer overflow. This issue arises when a client connects to an untrusted RFB/VNC server that improperly advertises a 16bpp framebuffer. If the server sends Hextile-encoded updates, the processing of the Hextile background fill can lead to a scenario where 32-bit pixel values are incorrectly written into a buffer that is allocated for only 16-bit pixels. This mismatch results in an out-of-bounds heap write, which may lead to a denial of service, characterized by unexpected process crashes, as well as potential memory corruption.

References

https://access.redhat.com/security/cve/CVE-2026-59691
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2497343
issue-trackingx_refsource_REDHAT
https://gitlab.freedesktop.org/gstreamer/gstreamer-securi...

CVSS V3.1

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Clouditera Security (Clouditera), NSFOCUS (NSFOCUS), and Z.ai Security (Z.ai) for reporting this issue.
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