How severe is CVE-1999-1553?

CVE-1999-1553 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-1999-1553 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1553?

CVE-1999-1553 affects Xcmail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-1553?

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-1999-1553 published?

CVE-1999-1553 was published on 1999-05-01 and last updated on 2026-06-16.

CVE-1999-1553

CVE-1999-1553 is a critical-severity vulnerability in Xcmail with a CVSS 2.0 base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 2.0 base score 10.0)
EPSS exploit prediction: 6% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Xcmail
Published: 1999-05-01
Last modified: 2026-06-16

Description

Buffer overflow in XCmail 0.99.6 with autoquote enabled allows remote attackers to execute arbitrary commands via a long subject line.

Frequently asked questions

What is CVE-1999-1553?: Buffer overflow in XCmail 0.99.6 with autoquote enabled allows remote attackers to execute arbitrary commands via a long subject line.
How severe is CVE-1999-1553?: CVE-1999-1553 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-1999-1553 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1553?: CVE-1999-1553 affects Xcmail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-1553?: 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-1999-1553 published?: CVE-1999-1553 was published on 1999-05-01 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:xcmail:xcmail:0.99.6:*:*:*:*:*:*:*