What is CVE-1999-0526?

CVE-1999-0526 is a vulnerability in X.org X11. Published 1997-07-01.

Is CVE-1999-0526 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in X.org X11

CVE-1999-0526

An X server's access control is disabled (e.g. through an "xhost +" command) and allows anyone to connect to the server.

Published 1997-07-01 · last modified 2026-06-16.

CVSS v2 metric

CVSS v2 base score 10.0 (High). Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.208 (97.5th percentile), scored 2026-10-31.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 97.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.208 · newest: 0.208 · change: 0.000

Affected products

X.org X11 — versions 7.1_1.1.0

Public proof-of-concept exploits

References

www.kb.cert.org/vuls/id/704969 (US Government Resource, third-party-advisory)

Frequently asked questions

What is CVE-1999-0526?: CVE-1999-0526 is a vulnerability in X.org X11. Published 1997-07-01.
Is CVE-1999-0526 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.