The XListFonts function in X.org libX11 before 1.6.4 might allow remote X servers to gain…
Priority MEDIUM 49CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
EPSS 0.04459 91st percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:* | 25 | Vulnerable | Fedoraproject |
| cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:* | up to 1.6.3 | Vulnerable | x.org |
- cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:* Versions 25 Vulnerable ·Fedoraproject
- cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:* Versions up to 1.6.3 Vulnerable ·x.org
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Timeline
- 2026-10-02 Threatist record created from CVE-2016-7943
- 2026-10-03 Alias added: GHSA-84fh-jqg7-vh26
References
Other 4
- https://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=8c29f1607a31dac0911e45a0dd3d74173822b3c9
- [xorg-announce] 20161004 X.Org security advisory: Protocol handling issues in X Window System client libraries
- [oss-security] 20161004 Re: X.Org security advisory: Protocol handling issues in X Window System client libraries
- [oss-security] 20161004 X.Org security advisory: Protocol handling issues in X Window System client libraries
Sources
- CVE-2016-7943 · CVE Program
- CVE-2016-7943 · NVD
- FIRST EPSS
- GHSA-84fh-jqg7-vh26 · GitHub Advisory Database · CC BY 4.0
- CVE-2016-7943 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences