CVE-2016-9942

critical

Published 2016-12-31 · Modified 2026-05-06

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CVSS v3

9.8

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v4 NEW

—

not yet in upstream

VIR risk

9.8

Description

Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds what is specified by the tile dimensions.

Predictions

Exploit likelihood

97%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Arch Fixed 1 release

Version	Status	Fixed in
—	Fixed	`0.9.11-1`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`0.9.11+dfsg-1`
sid	Fixed	`0.9.11+dfsg-1`
forky	Fixed	`0.9.11+dfsg-1`
bullseye	Fixed	`0.9.11+dfsg-1`
bookworm	Fixed	`0.9.11+dfsg-1`

Application impact

Vendor	Product	Versions	Fixed
libvncserver_project	libvncserver	`0.9.10`

References

CWEs

CWE-119

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.