CVE-2016-7943

critical

Published 2016-12-13 · Modified 2026-05-06

💬 Discuss on Community ✚ Propose mitigation

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

The XListFonts function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involving length fields, which trigger out-of-bounds write operations.

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

Fedora Affected 1 release

Version	Status	Fixed in
25	Affected	—

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`2:1.6.4-1`
sid	Fixed	`2:1.6.4-1`
forky	Fixed	`2:1.6.4-1`
bullseye	Fixed	`2:1.6.4-1`
bookworm	Fixed	`2:1.6.4-1`

Application impact

Vendor	Product	Versions	Fixed
x.org	libx11	`{"endIncluding":"1.6.3"}`

References

CWEs

CWE-787

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

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