How severe is CVE-1999-0526?

CVE-1999-0526 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-1999-0526 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0526?

CVE-1999-0526 affects X.org X11. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-0526?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-1999-0526 published?

CVE-1999-0526 was published on 1997-07-01 and last updated on 2026-06-16.

CVE-1999-0526

CVE-1999-0526 is a critical-severity vulnerability in X.org X11 with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 21% places it in the 97th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Critical (CVSS 2.0 base score 10.0)
EPSS exploit prediction: 21% (97th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: X.org X11
Published: 1997-07-01
Last modified: 2026-06-16

Description

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

Frequently asked questions

What is 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.
How severe is CVE-1999-0526?: CVE-1999-0526 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-1999-0526 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0526?: CVE-1999-0526 affects X.org X11. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-0526?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-1999-0526 published?: CVE-1999-0526 was published on 1997-07-01 and last updated on 2026-06-16.

References

http://www.kb.cert.org/vuls/id/704969

Affected products (1)

cpe:2.3:a:x.org:x11:7.1_1.1.0:*:*:*:*:*:*:*

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