CVE-2021-21811
CVSS v3
9.8
CRITICAL
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
A memory corruption vulnerability exists in the XML-parsing CreateLabelOrAttrib functionality of AT&T Labs’ Xmill 0.7. A specially crafted XML file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.
Technical details
- Published
- 2021-08-31
Frequently asked questions
What is CVE-2021-21811?
A memory corruption vulnerability exists in the XML-parsing CreateLabelOrAttrib functionality of AT&T Labs’ Xmill 0.7. A specially crafted XML file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.
Is CVE-2021-21811 actively exploited?
Active exploitation of CVE-2021-21811 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-21811?
CVE-2021-21811 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2021-21811 affecting your environment?
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